xref: /freebsd/contrib/ncurses/form/frm_driver.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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2  * Copyright (c) 1998-2013,2014 Free Software Foundation, Inc.              *
3  *                                                                          *
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14  *                                                                          *
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22  *                                                                          *
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28 
29 /****************************************************************************
30  *   Author:  Juergen Pfeifer, 1995,1997                                    *
31  ****************************************************************************/
32 
33 #include "form.priv.h"
34 
35 MODULE_ID("$Id: frm_driver.c,v 1.110 2014/02/10 00:42:48 tom Exp $")
36 
37 /*----------------------------------------------------------------------------
38   This is the core module of the form library. It contains the majority
39   of the driver routines as well as the form_driver function.
40 
41   Essentially this module is nearly the whole library. This is because
42   all the functions in this module depends on some others in the module,
43   so it makes no sense to split them into separate files because they
44   will always be linked together. The only acceptable concern is turnaround
45   time for this module, but now we have all Pentiums or RISCs, so what!
46 
47   The driver routines are grouped into nine generic categories:
48 
49    a)   Page Navigation            ( all functions prefixed by PN_ )
50         The current page of the form is left and some new page is
51         entered.
52    b)   Inter-Field Navigation     ( all functions prefixed by FN_ )
53         The current field of the form is left and some new field is
54         entered.
55    c)   Intra-Field Navigation     ( all functions prefixed by IFN_ )
56         The current position in the current field is changed.
57    d)   Vertical Scrolling         ( all functions prefixed by VSC_ )
58         Essentially this is a specialization of Intra-Field navigation.
59         It has to check for a multi-line field.
60    e)   Horizontal Scrolling       ( all functions prefixed by HSC_ )
61         Essentially this is a specialization of Intra-Field navigation.
62         It has to check for a single-line field.
63    f)   Field Editing              ( all functions prefixed by FE_ )
64         The content of the current field is changed
65    g)   Edit Mode requests         ( all functions prefixed by EM_ )
66         Switching between insert and overlay mode
67    h)   Field-Validation requests  ( all functions prefixed by FV_ )
68         Perform verifications of the field.
69    i)   Choice requests            ( all functions prefixed by CR_ )
70         Requests to enumerate possible field values
71   --------------------------------------------------------------------------*/
72 
73 /*----------------------------------------------------------------------------
74   Some remarks on the placements of assert() macros :
75   I use them only on "strategic" places, i.e. top level entries where
76   I want to make sure that things are set correctly. Throughout subordinate
77   routines I omit them mostly.
78   --------------------------------------------------------------------------*/
79 
80 /*
81 Some options that may effect compatibility in behavior to SVr4 forms,
82 but they are here to allow a more intuitive and user friendly behavior of
83 our form implementation. This doesn't affect the API, so we feel it is
84 uncritical.
85 
86 The initial implementation tries to stay very close with the behavior
87 of the original SVr4 implementation, although in some areas it is quite
88 clear that this isn't the most appropriate way. As far as possible this
89 sources will allow you to build a forms lib that behaves quite similar
90 to SVr4, but now and in the future we will give you better options.
91 Perhaps at some time we will make this configurable at runtime.
92 */
93 
94 /* Implement a more user-friendly previous/next word behavior */
95 #define FRIENDLY_PREV_NEXT_WORD (1)
96 /* Fix the wrong behavior for forms with all fields inactive */
97 #define FIX_FORM_INACTIVE_BUG (1)
98 /* Allow dynamic field growth also when navigating past the end */
99 #define GROW_IF_NAVIGATE (1)
100 
101 #if USE_WIDEC_SUPPORT
102 #define myADDNSTR(w, s, n) wadd_wchnstr(w, s, n)
103 #define myINSNSTR(w, s, n) wins_wchnstr(w, s, n)
104 #define myINNSTR(w, s, n)  fix_wchnstr(w, s, n)
105 #define myWCWIDTH(w, y, x) cell_width(w, y, x)
106 #else
107 #define myADDNSTR(w, s, n) waddnstr(w, s, n)
108 #define myINSNSTR(w, s, n) winsnstr(w, s, n)
109 #define myINNSTR(w, s, n)  winnstr(w, s, n)
110 #define myWCWIDTH(w, y, x) 1
111 #endif
112 
113 /*----------------------------------------------------------------------------
114   Forward references to some internally used static functions
115   --------------------------------------------------------------------------*/
116 static int Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form);
117 static int FN_Next_Field(FORM *form);
118 static int FN_Previous_Field(FORM *form);
119 static int FE_New_Line(FORM *);
120 static int FE_Delete_Previous(FORM *);
121 
122 /*----------------------------------------------------------------------------
123   Macro Definitions.
124 
125   Some Remarks on that: I use the convention to use UPPERCASE for constants
126   defined by Macros. If I provide a macro as a kind of inline routine to
127   provide some logic, I use my Upper_Lower case style.
128   --------------------------------------------------------------------------*/
129 
130 /* Calculate the position of a single row in a field buffer */
131 #define Position_Of_Row_In_Buffer(field,row) ((row)*(field)->dcols)
132 
133 /* Calculate start address for the fields buffer# N */
134 #define Address_Of_Nth_Buffer(field,N) \
135   ((field)->buf + (N)*(1+Buffer_Length(field)))
136 
137 /* Calculate the start address of the row in the fields specified buffer# N */
138 #define Address_Of_Row_In_Nth_Buffer(field,N,row) \
139   (Address_Of_Nth_Buffer(field,N) + Position_Of_Row_In_Buffer(field,row))
140 
141 /* Calculate the start address of the row in the fields primary buffer */
142 #define Address_Of_Row_In_Buffer(field,row) \
143   Address_Of_Row_In_Nth_Buffer(field,0,row)
144 
145 /* Calculate the start address of the row in the forms current field
146    buffer# N */
147 #define Address_Of_Current_Row_In_Nth_Buffer(form,N) \
148    Address_Of_Row_In_Nth_Buffer((form)->current,N,(form)->currow)
149 
150 /* Calculate the start address of the row in the forms current field
151    primary buffer */
152 #define Address_Of_Current_Row_In_Buffer(form) \
153    Address_Of_Current_Row_In_Nth_Buffer(form,0)
154 
155 /* Calculate the address of the cursor in the forms current field
156    primary buffer */
157 #define Address_Of_Current_Position_In_Nth_Buffer(form,N) \
158    (Address_Of_Current_Row_In_Nth_Buffer(form,N) + (form)->curcol)
159 
160 /* Calculate the address of the cursor in the forms current field
161    buffer# N */
162 #define Address_Of_Current_Position_In_Buffer(form) \
163   Address_Of_Current_Position_In_Nth_Buffer(form,0)
164 
165 /* Logic to decide whether or not a field is actually a field with
166    vertical or horizontal scrolling */
167 #define Is_Scroll_Field(field)          \
168    (((field)->drows > (field)->rows) || \
169     ((field)->dcols > (field)->cols))
170 
171 /* Logic to decide whether or not a field needs to have an individual window
172    instead of a derived window because it contains invisible parts.
173    This is true for non-public fields and for scrollable fields. */
174 #define Has_Invisible_Parts(field)     \
175   (!((unsigned)(field)->opts & O_PUBLIC) || \
176    Is_Scroll_Field(field))
177 
178 /* Logic to decide whether or not a field needs justification */
179 #define Justification_Allowed(field)        \
180    (((field)->just != NO_JUSTIFICATION)  && \
181     (Single_Line_Field(field))           && \
182     (((field)->dcols == (field)->cols)   && \
183     ((unsigned)(field)->opts & O_STATIC)))
184 
185 /* Logic to determine whether or not a dynamic field may still grow */
186 #define Growable(field) ((field)->status & _MAY_GROW)
187 
188 /* Macro to set the attributes for a fields window */
189 #define Set_Field_Window_Attributes(field,win) \
190 (  wbkgdset((win),(chtype)((chtype)((field)->pad) | (field)->back)), \
191    (void) wattrset((win), (int)(field)->fore) )
192 
193 /* Logic to decide whether or not a field really appears on the form */
194 #define Field_Really_Appears(field)         \
195   ((field->form)                          &&\
196    (field->form->status & _POSTED)        &&\
197    ((unsigned)field->opts & O_VISIBLE)    &&\
198    (field->page == field->form->curpage))
199 
200 /* Logic to determine whether or not we are on the first position in the
201    current field */
202 #define First_Position_In_Current_Field(form) \
203   (((form)->currow==0) && ((form)->curcol==0))
204 
205 #define Minimum(a,b) (((a)<=(b)) ? (a) : (b))
206 #define Maximum(a,b) (((a)>=(b)) ? (a) : (b))
207 
208 /*----------------------------------------------------------------------------
209   Useful constants
210   --------------------------------------------------------------------------*/
211 static FIELD_CELL myBLANK = BLANK;
212 static FIELD_CELL myZEROS;
213 
214 #ifdef TRACE
215 static void
216 check_pos(FORM *form, int lineno)
217 {
218   int y, x;
219 
220   if (form && form->w)
221     {
222       getyx(form->w, y, x);
223       if (y != form->currow || x != form->curcol)
224 	{
225 	  T(("CHECKPOS %s@%d have position %d,%d vs want %d,%d",
226 	     __FILE__, lineno,
227 	     y, x,
228 	     form->currow, form->curcol));
229 	}
230     }
231 }
232 #define CHECKPOS(form) check_pos(form, __LINE__)
233 #else
234 #define CHECKPOS(form)		/* nothing */
235 #endif
236 
237 /*----------------------------------------------------------------------------
238   Wide-character special functions
239   --------------------------------------------------------------------------*/
240 #if USE_WIDEC_SUPPORT
241 /* like winsnstr */
242 static int
243 wins_wchnstr(WINDOW *w, cchar_t *s, int n)
244 {
245   int code = ERR;
246   int y, x;
247 
248   while (n-- > 0)
249     {
250       getyx(w, y, x);
251       if ((code = wins_wch(w, s++)) != OK)
252 	break;
253       if ((code = wmove(w, y, x + 1)) != OK)
254 	break;
255     }
256   return code;
257 }
258 
259 /* win_wchnstr is inconsistent with winnstr, since it returns OK rather than
260  * the number of items transferred.
261  */
262 static int
263 fix_wchnstr(WINDOW *w, cchar_t *s, int n)
264 {
265   int x;
266 
267   win_wchnstr(w, s, n);
268   /*
269    * This function is used to extract the text only from the window.
270    * Strip attributes and color from the string so they will not be added
271    * back when copying the string to the window.
272    */
273   for (x = 0; x < n; ++x)
274     {
275       RemAttr(s[x], A_ATTRIBUTES);
276       SetPair(s[x], 0);
277     }
278   return n;
279 }
280 
281 /*
282  * Returns the column of the base of the given cell.
283  */
284 static int
285 cell_base(WINDOW *win, int y, int x)
286 {
287   int result = x;
288 
289   while (LEGALYX(win, y, x))
290     {
291       cchar_t *data = &(win->_line[y].text[x]);
292 
293       if (isWidecBase(CHDEREF(data)) || !isWidecExt(CHDEREF(data)))
294 	{
295 	  result = x;
296 	  break;
297 	}
298       --x;
299     }
300   return result;
301 }
302 
303 /*
304  * Returns the number of columns needed for the given cell in a window.
305  */
306 static int
307 cell_width(WINDOW *win, int y, int x)
308 {
309   int result = 1;
310 
311   if (LEGALYX(win, y, x))
312     {
313       cchar_t *data = &(win->_line[y].text[x]);
314 
315       if (isWidecExt(CHDEREF(data)))
316 	{
317 	  /* recur, providing the number of columns to the next character */
318 	  result = cell_width(win, y, x - 1);
319 	}
320       else
321 	{
322 	  result = wcwidth(CharOf(CHDEREF(data)));
323 	}
324     }
325   return result;
326 }
327 
328 /*
329  * There is no wide-character function such as wdel_wch(), so we must find
330  * all of the cells that comprise a multi-column character and delete them
331  * one-by-one.
332  */
333 static void
334 delete_char(FORM *form)
335 {
336   int cells = cell_width(form->w, form->currow, form->curcol);
337 
338   form->curcol = cell_base(form->w, form->currow, form->curcol);
339   wmove(form->w, form->currow, form->curcol);
340   while (cells-- > 0)
341     {
342       wdelch(form->w);
343     }
344 }
345 #define DeleteChar(form) delete_char(form)
346 #else
347 #define DeleteChar(form) \
348 	  wmove((form)->w, (form)->currow, (form)->curcol), \
349 	  wdelch((form)->w)
350 #endif
351 
352 /*---------------------------------------------------------------------------
353 |   Facility      :  libnform
354 |   Function      :  static char *Get_Start_Of_Data(char * buf, int blen)
355 |
356 |   Description   :  Return pointer to first non-blank position in buffer.
357 |                    If buffer is empty return pointer to buffer itself.
358 |
359 |   Return Values :  Pointer to first non-blank position in buffer
360 +--------------------------------------------------------------------------*/
361 NCURSES_INLINE static FIELD_CELL *
362 Get_Start_Of_Data(FIELD_CELL *buf, int blen)
363 {
364   FIELD_CELL *p = buf;
365   FIELD_CELL *end = &buf[blen];
366 
367   assert(buf && blen >= 0);
368   while ((p < end) && ISBLANK(*p))
369     p++;
370   return ((p == end) ? buf : p);
371 }
372 
373 /*---------------------------------------------------------------------------
374 |   Facility      :  libnform
375 |   Function      :  static char *After_End_Of_Data(char * buf, int blen)
376 |
377 |   Description   :  Return pointer after last non-blank position in buffer.
378 |                    If buffer is empty, return pointer to buffer itself.
379 |
380 |   Return Values :  Pointer to position after last non-blank position in
381 |                    buffer.
382 +--------------------------------------------------------------------------*/
383 NCURSES_INLINE static FIELD_CELL *
384 After_End_Of_Data(FIELD_CELL *buf, int blen)
385 {
386   FIELD_CELL *p = &buf[blen];
387 
388   assert(buf && blen >= 0);
389   while ((p > buf) && ISBLANK(p[-1]))
390     p--;
391   return (p);
392 }
393 
394 /*---------------------------------------------------------------------------
395 |   Facility      :  libnform
396 |   Function      :  static char *Get_First_Whitespace_Character(
397 |                                     char * buf, int   blen)
398 |
399 |   Description   :  Position to the first whitespace character.
400 |
401 |   Return Values :  Pointer to first whitespace character in buffer.
402 +--------------------------------------------------------------------------*/
403 NCURSES_INLINE static FIELD_CELL *
404 Get_First_Whitespace_Character(FIELD_CELL *buf, int blen)
405 {
406   FIELD_CELL *p = buf;
407   FIELD_CELL *end = &p[blen];
408 
409   assert(buf && blen >= 0);
410   while ((p < end) && !ISBLANK(*p))
411     p++;
412   return ((p == end) ? buf : p);
413 }
414 
415 /*---------------------------------------------------------------------------
416 |   Facility      :  libnform
417 |   Function      :  static char *After_Last_Whitespace_Character(
418 |                                     char * buf, int blen)
419 |
420 |   Description   :  Get the position after the last whitespace character.
421 |
422 |   Return Values :  Pointer to position after last whitespace character in
423 |                    buffer.
424 +--------------------------------------------------------------------------*/
425 NCURSES_INLINE static FIELD_CELL *
426 After_Last_Whitespace_Character(FIELD_CELL *buf, int blen)
427 {
428   FIELD_CELL *p = &buf[blen];
429 
430   assert(buf && blen >= 0);
431   while ((p > buf) && !ISBLANK(p[-1]))
432     p--;
433   return (p);
434 }
435 
436 /* Set this to 1 to use the div_t version. This is a good idea if your
437    compiler has an intrinsic div() support. Unfortunately GNU-C has it
438    not yet.
439    N.B.: This only works if form->curcol follows immediately form->currow
440          and both are of type int.
441 */
442 #define USE_DIV_T (0)
443 
444 /*---------------------------------------------------------------------------
445 |   Facility      :  libnform
446 |   Function      :  static void Adjust_Cursor_Position(
447 |                                       FORM * form, const char * pos)
448 |
449 |   Description   :  Set current row and column of the form to values
450 |                    corresponding to the buffer position.
451 |
452 |   Return Values :  -
453 +--------------------------------------------------------------------------*/
454 NCURSES_INLINE static void
455 Adjust_Cursor_Position(FORM *form, const FIELD_CELL *pos)
456 {
457   FIELD *field;
458   int idx;
459 
460   field = form->current;
461   assert(pos >= field->buf && field->dcols > 0);
462   idx = (int)(pos - field->buf);
463 #if USE_DIV_T
464   *((div_t *) & (form->currow)) = div(idx, field->dcols);
465 #else
466   form->currow = idx / field->dcols;
467   form->curcol = idx - field->cols * form->currow;
468 #endif
469   if (field->drows < form->currow)
470     form->currow = 0;
471 }
472 
473 /*---------------------------------------------------------------------------
474 |   Facility      :  libnform
475 |   Function      :  static void Buffer_To_Window(
476 |                                      const FIELD  * field,
477 |                                      WINDOW * win)
478 |
479 |   Description   :  Copy the buffer to the window. If it is a multi-line
480 |                    field, the buffer is split to the lines of the
481 |                    window without any editing.
482 |
483 |   Return Values :  -
484 +--------------------------------------------------------------------------*/
485 static void
486 Buffer_To_Window(const FIELD *field, WINDOW *win)
487 {
488   int width, height;
489   int y, x;
490   int len;
491   int row;
492   FIELD_CELL *pBuffer;
493 
494   assert(win && field);
495 
496   getyx(win, y, x);
497   width = getmaxx(win);
498   height = getmaxy(win);
499 
500   for (row = 0, pBuffer = field->buf;
501        row < height;
502        row++, pBuffer += width)
503     {
504       if ((len = (int)(After_End_Of_Data(pBuffer, width) - pBuffer)) > 0)
505 	{
506 	  wmove(win, row, 0);
507 	  myADDNSTR(win, pBuffer, len);
508 	}
509     }
510   wmove(win, y, x);
511 }
512 
513 /*---------------------------------------------------------------------------
514 |   Facility      :  libnform
515 |   Function      :  void _nc_get_fieldbuffer(
516 |                                          WINDOW * win,
517 |                                          FIELD  * field,
518 |                                          FIELD_CELL * buf)
519 |
520 |   Description   :  Copy the content of the window into the buffer.
521 |                    The multiple lines of a window are simply
522 |                    concatenated into the buffer. Pad characters in
523 |                    the window will be replaced by blanks in the buffer.
524 |
525 |   Return Values :  -
526 +--------------------------------------------------------------------------*/
527 NCURSES_EXPORT(void)
528 _nc_get_fieldbuffer(FORM *form, FIELD *field, FIELD_CELL *buf)
529 {
530   int pad;
531   int len = 0;
532   FIELD_CELL *p;
533   int row, height;
534   WINDOW *win;
535 
536   assert(form && field && buf);
537 
538   win = form->w;
539   assert(win);
540 
541   pad = field->pad;
542   p = buf;
543   height = getmaxy(win);
544 
545   for (row = 0; (row < height) && (row < field->drows); row++)
546     {
547       wmove(win, row, 0);
548       len += myINNSTR(win, p + len, field->dcols);
549     }
550   p[len] = myZEROS;
551 
552   /* replace visual padding character by blanks in buffer */
553   if (pad != C_BLANK)
554     {
555       int i;
556 
557       for (i = 0; i < len; i++, p++)
558 	{
559 	  if ((unsigned long)CharOf(*p) == ChCharOf(pad)
560 #if USE_WIDEC_SUPPORT
561 	      && p->chars[1] == 0
562 #endif
563 	    )
564 	    *p = myBLANK;
565 	}
566     }
567 }
568 
569 /*---------------------------------------------------------------------------
570 |   Facility      :  libnform
571 |   Function      :  static void Window_To_Buffer(
572 |                                          FORM   * form,
573 |                                          FIELD  * field)
574 |
575 |   Description   :  Copy the content of the window into the buffer.
576 |                    The multiple lines of a window are simply
577 |                    concatenated into the buffer. Pad characters in
578 |                    the window will be replaced by blanks in the buffer.
579 |
580 |   Return Values :  -
581 +--------------------------------------------------------------------------*/
582 static void
583 Window_To_Buffer(FORM *form, FIELD *field)
584 {
585   _nc_get_fieldbuffer(form, field, field->buf);
586 }
587 
588 /*---------------------------------------------------------------------------
589 |   Facility      :  libnform
590 |   Function      :  static void Synchronize_Buffer(FORM * form)
591 |
592 |   Description   :  If there was a change, copy the content of the
593 |                    window into the buffer, so the buffer is synchronized
594 |                    with the windows content. We have to indicate that the
595 |                    buffer needs validation due to the change.
596 |
597 |   Return Values :  -
598 +--------------------------------------------------------------------------*/
599 NCURSES_INLINE static void
600 Synchronize_Buffer(FORM *form)
601 {
602   if (form->status & _WINDOW_MODIFIED)
603     {
604       ClrStatus(form, _WINDOW_MODIFIED);
605       SetStatus(form, _FCHECK_REQUIRED);
606       Window_To_Buffer(form, form->current);
607       wmove(form->w, form->currow, form->curcol);
608     }
609 }
610 
611 /*---------------------------------------------------------------------------
612 |   Facility      :  libnform
613 |   Function      :  static bool Field_Grown( FIELD *field, int amount)
614 |
615 |   Description   :  This function is called for growable dynamic fields
616 |                    only. It has to increase the buffers and to allocate
617 |                    a new window for this field.
618 |                    This function has the side effect to set a new
619 |                    field-buffer pointer, the dcols and drows values
620 |                    as well as a new current Window for the field.
621 |
622 |   Return Values :  TRUE     - field successfully increased
623 |                    FALSE    - there was some error
624 +--------------------------------------------------------------------------*/
625 static bool
626 Field_Grown(FIELD *field, int amount)
627 {
628   bool result = FALSE;
629 
630   if (field && Growable(field))
631     {
632       bool single_line_field = Single_Line_Field(field);
633       int old_buflen = Buffer_Length(field);
634       int new_buflen;
635       int old_dcols = field->dcols;
636       int old_drows = field->drows;
637       FIELD_CELL *oldbuf = field->buf;
638       FIELD_CELL *newbuf;
639 
640       int growth;
641       FORM *form = field->form;
642       bool need_visual_update = ((form != (FORM *)0) &&
643 				 (form->status & _POSTED) &&
644 				 (form->current == field));
645 
646       if (need_visual_update)
647 	Synchronize_Buffer(form);
648 
649       if (single_line_field)
650 	{
651 	  growth = field->cols * amount;
652 	  if (field->maxgrow)
653 	    growth = Minimum(field->maxgrow - field->dcols, growth);
654 	  field->dcols += growth;
655 	  if (field->dcols == field->maxgrow)
656 	    ClrStatus(field, _MAY_GROW);
657 	}
658       else
659 	{
660 	  growth = (field->rows + field->nrow) * amount;
661 	  if (field->maxgrow)
662 	    growth = Minimum(field->maxgrow - field->drows, growth);
663 	  field->drows += growth;
664 	  if (field->drows == field->maxgrow)
665 	    ClrStatus(field, _MAY_GROW);
666 	}
667       /* drows, dcols changed, so we get really the new buffer length */
668       new_buflen = Buffer_Length(field);
669       newbuf = (FIELD_CELL *)malloc(Total_Buffer_Size(field));
670       if (!newbuf)
671 	{
672 	  /* restore to previous state */
673 	  field->dcols = old_dcols;
674 	  field->drows = old_drows;
675 	  if ((single_line_field && (field->dcols != field->maxgrow)) ||
676 	      (!single_line_field && (field->drows != field->maxgrow)))
677 	    SetStatus(field, _MAY_GROW);
678 	}
679       else
680 	{
681 	  /* Copy all the buffers.  This is the reason why we can't just use
682 	   * realloc().
683 	   */
684 	  int i, j;
685 	  FIELD_CELL *old_bp;
686 	  FIELD_CELL *new_bp;
687 
688 	  result = TRUE;	/* allow sharing of recovery on failure */
689 
690 	  T((T_CREATE("fieldcell %p"), (void *)newbuf));
691 	  field->buf = newbuf;
692 	  for (i = 0; i <= field->nbuf; i++)
693 	    {
694 	      new_bp = Address_Of_Nth_Buffer(field, i);
695 	      old_bp = oldbuf + i * (1 + old_buflen);
696 	      for (j = 0; j < old_buflen; ++j)
697 		new_bp[j] = old_bp[j];
698 	      while (j < new_buflen)
699 		new_bp[j++] = myBLANK;
700 	      new_bp[new_buflen] = myZEROS;
701 	    }
702 
703 #if USE_WIDEC_SUPPORT && NCURSES_EXT_FUNCS
704 	  if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
705 	    result = FALSE;
706 #endif
707 
708 	  if (need_visual_update && result)
709 	    {
710 	      WINDOW *new_window = newpad(field->drows, field->dcols);
711 
712 	      if (new_window != 0)
713 		{
714 		  assert(form != (FORM *)0);
715 		  if (form->w)
716 		    delwin(form->w);
717 		  form->w = new_window;
718 		  Set_Field_Window_Attributes(field, form->w);
719 		  werase(form->w);
720 		  Buffer_To_Window(field, form->w);
721 		  untouchwin(form->w);
722 		  wmove(form->w, form->currow, form->curcol);
723 		}
724 	      else
725 		result = FALSE;
726 	    }
727 
728 	  if (result)
729 	    {
730 	      free(oldbuf);
731 	      /* reflect changes in linked fields */
732 	      if (field != field->link)
733 		{
734 		  FIELD *linked_field;
735 
736 		  for (linked_field = field->link;
737 		       linked_field != field;
738 		       linked_field = linked_field->link)
739 		    {
740 		      linked_field->buf = field->buf;
741 		      linked_field->drows = field->drows;
742 		      linked_field->dcols = field->dcols;
743 		    }
744 		}
745 	    }
746 	  else
747 	    {
748 	      /* restore old state */
749 	      field->dcols = old_dcols;
750 	      field->drows = old_drows;
751 	      field->buf = oldbuf;
752 	      if ((single_line_field &&
753 		   (field->dcols != field->maxgrow)) ||
754 		  (!single_line_field &&
755 		   (field->drows != field->maxgrow)))
756 		SetStatus(field, _MAY_GROW);
757 	      free(newbuf);
758 	    }
759 	}
760     }
761   return (result);
762 }
763 
764 #ifdef NCURSES_MOUSE_VERSION
765 /*---------------------------------------------------------------------------
766 |   Facility      :  libnform
767 |   Function      :  int Field_encloses(FIELD *field, int ry, int rx)
768 |
769 |   Description   :  Check if the given coordinates lie within the given field.
770 |
771 |   Return Values :  E_OK              - success
772 |                    E_BAD_ARGUMENT    - invalid form pointer
773 |                    E_SYSTEM_ERROR    - form has no current field or
774 |                                        field-window
775 +--------------------------------------------------------------------------*/
776 static int
777 Field_encloses(FIELD *field, int ry, int rx)
778 {
779   T((T_CALLED("Field_encloses(%p)"), (void *)field));
780   if (field != 0
781       && field->frow <= ry
782       && (field->frow + field->rows) > ry
783       && field->fcol <= rx
784       && (field->fcol + field->cols) > rx)
785     {
786       RETURN(E_OK);
787     }
788   RETURN(E_INVALID_FIELD);
789 }
790 #endif
791 
792 /*---------------------------------------------------------------------------
793 |   Facility      :  libnform
794 |   Function      :  int _nc_Position_Form_Cursor(FORM * form)
795 |
796 |   Description   :  Position the cursor in the window for the current
797 |                    field to be in sync. with the currow and curcol
798 |                    values.
799 |
800 |   Return Values :  E_OK              - success
801 |                    E_BAD_ARGUMENT    - invalid form pointer
802 |                    E_SYSTEM_ERROR    - form has no current field or
803 |                                        field-window
804 +--------------------------------------------------------------------------*/
805 NCURSES_EXPORT(int)
806 _nc_Position_Form_Cursor(FORM *form)
807 {
808   FIELD *field;
809   WINDOW *formwin;
810 
811   if (!form)
812     return (E_BAD_ARGUMENT);
813 
814   if (!form->w || !form->current)
815     return (E_SYSTEM_ERROR);
816 
817   field = form->current;
818   formwin = Get_Form_Window(form);
819 
820   wmove(form->w, form->currow, form->curcol);
821   if (Has_Invisible_Parts(field))
822     {
823       /* in this case fieldwin isn't derived from formwin, so we have
824          to move the cursor in formwin by hand... */
825       wmove(formwin,
826 	    field->frow + form->currow - form->toprow,
827 	    field->fcol + form->curcol - form->begincol);
828       wcursyncup(formwin);
829     }
830   else
831     wcursyncup(form->w);
832   return (E_OK);
833 }
834 
835 /*---------------------------------------------------------------------------
836 |   Facility      :  libnform
837 |   Function      :  int _nc_Refresh_Current_Field(FORM * form)
838 |
839 |   Description   :  Propagate the changes in the fields window to the
840 |                    window of the form.
841 |
842 |   Return Values :  E_OK              - on success
843 |                    E_BAD_ARGUMENT    - invalid form pointer
844 |                    E_SYSTEM_ERROR    - general error
845 +--------------------------------------------------------------------------*/
846 NCURSES_EXPORT(int)
847 _nc_Refresh_Current_Field(FORM *form)
848 {
849   WINDOW *formwin;
850   FIELD *field;
851 
852   T((T_CALLED("_nc_Refresh_Current_Field(%p)"), (void *)form));
853 
854   if (!form)
855     RETURN(E_BAD_ARGUMENT);
856 
857   if (!form->w || !form->current)
858     RETURN(E_SYSTEM_ERROR);
859 
860   field = form->current;
861   formwin = Get_Form_Window(form);
862 
863   if ((unsigned)field->opts & O_PUBLIC)
864     {
865       if (Is_Scroll_Field(field))
866 	{
867 	  /* Again, in this case the fieldwin isn't derived from formwin,
868 	     so we have to perform a copy operation. */
869 	  if (Single_Line_Field(field))
870 	    {
871 	      /* horizontal scrolling */
872 	      if (form->curcol < form->begincol)
873 		form->begincol = form->curcol;
874 	      else
875 		{
876 		  if (form->curcol >= (form->begincol + field->cols))
877 		    form->begincol = form->curcol - field->cols + 1;
878 		}
879 	      copywin(form->w,
880 		      formwin,
881 		      0,
882 		      form->begincol,
883 		      field->frow,
884 		      field->fcol,
885 		      field->frow,
886 		      field->cols + field->fcol - 1,
887 		      0);
888 	    }
889 	  else
890 	    {
891 	      /* A multi-line, i.e. vertical scrolling field */
892 	      int row_after_bottom, first_modified_row, first_unmodified_row;
893 
894 	      if (field->drows > field->rows)
895 		{
896 		  row_after_bottom = form->toprow + field->rows;
897 		  if (form->currow < form->toprow)
898 		    {
899 		      form->toprow = form->currow;
900 		      SetStatus(field, _NEWTOP);
901 		    }
902 		  if (form->currow >= row_after_bottom)
903 		    {
904 		      form->toprow = form->currow - field->rows + 1;
905 		      SetStatus(field, _NEWTOP);
906 		    }
907 		  if (field->status & _NEWTOP)
908 		    {
909 		      /* means we have to copy whole range */
910 		      first_modified_row = form->toprow;
911 		      first_unmodified_row = first_modified_row + field->rows;
912 		      ClrStatus(field, _NEWTOP);
913 		    }
914 		  else
915 		    {
916 		      /* we try to optimize : finding the range of touched
917 		         lines */
918 		      first_modified_row = form->toprow;
919 		      while (first_modified_row < row_after_bottom)
920 			{
921 			  if (is_linetouched(form->w, first_modified_row))
922 			    break;
923 			  first_modified_row++;
924 			}
925 		      first_unmodified_row = first_modified_row;
926 		      while (first_unmodified_row < row_after_bottom)
927 			{
928 			  if (!is_linetouched(form->w, first_unmodified_row))
929 			    break;
930 			  first_unmodified_row++;
931 			}
932 		    }
933 		}
934 	      else
935 		{
936 		  first_modified_row = form->toprow;
937 		  first_unmodified_row = first_modified_row + field->rows;
938 		}
939 	      if (first_unmodified_row != first_modified_row)
940 		copywin(form->w,
941 			formwin,
942 			first_modified_row,
943 			0,
944 			field->frow + first_modified_row - form->toprow,
945 			field->fcol,
946 			field->frow + first_unmodified_row - form->toprow - 1,
947 			field->cols + field->fcol - 1,
948 			0);
949 	    }
950 	  wsyncup(formwin);
951 	}
952       else
953 	{
954 	  /* if the field-window is simply a derived window, i.e. contains no
955 	   * invisible parts, the whole thing is trivial
956 	   */
957 	  wsyncup(form->w);
958 	}
959     }
960   untouchwin(form->w);
961   returnCode(_nc_Position_Form_Cursor(form));
962 }
963 
964 /*---------------------------------------------------------------------------
965 |   Facility      :  libnform
966 |   Function      :  static void Perform_Justification(
967 |                                        FIELD  * field,
968 |                                        WINDOW * win)
969 |
970 |   Description   :  Output field with requested justification
971 |
972 |   Return Values :  -
973 +--------------------------------------------------------------------------*/
974 static void
975 Perform_Justification(FIELD *field, WINDOW *win)
976 {
977   FIELD_CELL *bp;
978   int len;
979   int col = 0;
980 
981   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
982   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
983 
984   if (len > 0)
985     {
986       assert(win && (field->drows == 1) && (field->dcols == field->cols));
987 
988       switch (field->just)
989 	{
990 	case JUSTIFY_LEFT:
991 	  break;
992 	case JUSTIFY_CENTER:
993 	  col = (field->cols - len) / 2;
994 	  break;
995 	case JUSTIFY_RIGHT:
996 	  col = field->cols - len;
997 	  break;
998 	default:
999 	  break;
1000 	}
1001 
1002       wmove(win, 0, col);
1003       myADDNSTR(win, bp, len);
1004     }
1005 }
1006 
1007 /*---------------------------------------------------------------------------
1008 |   Facility      :  libnform
1009 |   Function      :  static void Undo_Justification(
1010 |                                     FIELD  * field,
1011 |                                     WINDOW * win)
1012 |
1013 |   Description   :  Display field without any justification, i.e.
1014 |                    left justified
1015 |
1016 |   Return Values :  -
1017 +--------------------------------------------------------------------------*/
1018 static void
1019 Undo_Justification(FIELD *field, WINDOW *win)
1020 {
1021   FIELD_CELL *bp;
1022   int len;
1023 
1024   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
1025   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
1026 
1027   if (len > 0)
1028     {
1029       assert(win);
1030       wmove(win, 0, 0);
1031       myADDNSTR(win, bp, len);
1032     }
1033 }
1034 
1035 /*---------------------------------------------------------------------------
1036 |   Facility      :  libnform
1037 |   Function      :  static bool Check_Char(FORM  *form,
1038 |                                           FIELD *field,
1039 |                                           FIELDTYPE * typ,
1040 |                                           int ch,
1041 |                                           TypeArgument *argp)
1042 |
1043 |   Description   :  Perform a single character check for character ch
1044 |                    according to the fieldtype instance.
1045 |
1046 |   Return Values :  TRUE             - Character is valid
1047 |                    FALSE            - Character is invalid
1048 +--------------------------------------------------------------------------*/
1049 static bool
1050 Check_Char(FORM *form,
1051 	   FIELD *field,
1052 	   FIELDTYPE *typ,
1053 	   int ch,
1054 	   TypeArgument *argp)
1055 {
1056   if (typ)
1057     {
1058       if (typ->status & _LINKED_TYPE)
1059 	{
1060 	  assert(argp);
1061 	  return (
1062 		   Check_Char(form, field, typ->left, ch, argp->left) ||
1063 		   Check_Char(form, field, typ->right, ch, argp->right));
1064 	}
1065       else
1066 	{
1067 #if NCURSES_INTEROP_FUNCS
1068 	  if (typ->charcheck.occheck)
1069 	    {
1070 	      if (typ->status & _GENERIC)
1071 		return typ->charcheck.gccheck(ch, form, field, (void *)argp);
1072 	      else
1073 		return typ->charcheck.occheck(ch, (void *)argp);
1074 	    }
1075 #else
1076 	  if (typ->ccheck)
1077 	    return typ->ccheck(ch, (void *)argp);
1078 #endif
1079 	}
1080     }
1081   return (!iscntrl(UChar(ch)) ? TRUE : FALSE);
1082 }
1083 
1084 /*---------------------------------------------------------------------------
1085 |   Facility      :  libnform
1086 |   Function      :  static int Display_Or_Erase_Field(
1087 |                                           FIELD * field,
1088 |                                           bool bEraseFlag)
1089 |
1090 |   Description   :  Create a subwindow for the field and display the
1091 |                    buffer contents (apply justification if required)
1092 |                    or simply erase the field.
1093 |
1094 |   Return Values :  E_OK           - on success
1095 |                    E_SYSTEM_ERROR - some error (typical no memory)
1096 +--------------------------------------------------------------------------*/
1097 static int
1098 Display_Or_Erase_Field(FIELD *field, bool bEraseFlag)
1099 {
1100   WINDOW *win;
1101   WINDOW *fwin;
1102 
1103   if (!field)
1104     return E_SYSTEM_ERROR;
1105 
1106   fwin = Get_Form_Window(field->form);
1107   win = derwin(fwin,
1108 	       field->rows, field->cols, field->frow, field->fcol);
1109 
1110   if (!win)
1111     return E_SYSTEM_ERROR;
1112   else
1113     {
1114       if ((unsigned)field->opts & O_VISIBLE)
1115 	{
1116 	  Set_Field_Window_Attributes(field, win);
1117 	}
1118       else
1119 	{
1120 	  (void)wattrset(win, (int)WINDOW_ATTRS(fwin));
1121 	}
1122       werase(win);
1123     }
1124 
1125   if (!bEraseFlag)
1126     {
1127       if ((unsigned)field->opts & O_PUBLIC)
1128 	{
1129 	  if (Justification_Allowed(field))
1130 	    Perform_Justification(field, win);
1131 	  else
1132 	    Buffer_To_Window(field, win);
1133 	}
1134       ClrStatus(field, _NEWTOP);
1135     }
1136   wsyncup(win);
1137   delwin(win);
1138   return E_OK;
1139 }
1140 
1141 /* Macros to preset the bEraseFlag */
1142 #define Display_Field(field) Display_Or_Erase_Field(field,FALSE)
1143 #define Erase_Field(field)   Display_Or_Erase_Field(field,TRUE)
1144 
1145 /*---------------------------------------------------------------------------
1146 |   Facility      :  libnform
1147 |   Function      :  static int Synchronize_Field(FIELD * field)
1148 |
1149 |   Description   :  Synchronize the windows content with the value in
1150 |                    the buffer.
1151 |
1152 |   Return Values :  E_OK                - success
1153 |                    E_BAD_ARGUMENT      - invalid field pointer
1154 |                    E_SYSTEM_ERROR      - some severe basic error
1155 +--------------------------------------------------------------------------*/
1156 static int
1157 Synchronize_Field(FIELD *field)
1158 {
1159   FORM *form;
1160   int res = E_OK;
1161 
1162   if (!field)
1163     return (E_BAD_ARGUMENT);
1164 
1165   if (((form = field->form) != (FORM *)0)
1166       && Field_Really_Appears(field))
1167     {
1168       if (field == form->current)
1169 	{
1170 	  form->currow = form->curcol = form->toprow = form->begincol = 0;
1171 	  werase(form->w);
1172 
1173 	  if (((unsigned)field->opts & O_PUBLIC) && Justification_Allowed(field))
1174 	    Undo_Justification(field, form->w);
1175 	  else
1176 	    Buffer_To_Window(field, form->w);
1177 
1178 	  SetStatus(field, _NEWTOP);
1179 	  res = _nc_Refresh_Current_Field(form);
1180 	}
1181       else
1182 	res = Display_Field(field);
1183     }
1184   SetStatus(field, _CHANGED);
1185   return (res);
1186 }
1187 
1188 /*---------------------------------------------------------------------------
1189 |   Facility      :  libnform
1190 |   Function      :  static int Synchronize_Linked_Fields(FIELD * field)
1191 |
1192 |   Description   :  Propagate the Synchronize_Field function to all linked
1193 |                    fields. The first error that occurs in the sequence
1194 |                    of updates is the return value.
1195 |
1196 |   Return Values :  E_OK                - success
1197 |                    E_BAD_ARGUMENT      - invalid field pointer
1198 |                    E_SYSTEM_ERROR      - some severe basic error
1199 +--------------------------------------------------------------------------*/
1200 static int
1201 Synchronize_Linked_Fields(FIELD *field)
1202 {
1203   FIELD *linked_field;
1204   int res = E_OK;
1205   int syncres;
1206 
1207   if (!field)
1208     return (E_BAD_ARGUMENT);
1209 
1210   if (!field->link)
1211     return (E_SYSTEM_ERROR);
1212 
1213   for (linked_field = field->link;
1214        (linked_field != field) && (linked_field != 0);
1215        linked_field = linked_field->link)
1216     {
1217       if (((syncres = Synchronize_Field(linked_field)) != E_OK) &&
1218 	  (res == E_OK))
1219 	res = syncres;
1220     }
1221   return (res);
1222 }
1223 
1224 /*---------------------------------------------------------------------------
1225 |   Facility      :  libnform
1226 |   Function      :  int _nc_Synchronize_Attributes(FIELD * field)
1227 |
1228 |   Description   :  If a fields visual attributes have changed, this
1229 |                    routine is called to propagate those changes to the
1230 |                    screen.
1231 |
1232 |   Return Values :  E_OK             - success
1233 |                    E_BAD_ARGUMENT   - invalid field pointer
1234 |                    E_SYSTEM_ERROR   - some severe basic error
1235 +--------------------------------------------------------------------------*/
1236 NCURSES_EXPORT(int)
1237 _nc_Synchronize_Attributes(FIELD *field)
1238 {
1239   FORM *form;
1240   int res = E_OK;
1241   WINDOW *formwin;
1242 
1243   T((T_CALLED("_nc_Synchronize_Attributes(%p)"), (void *)field));
1244 
1245   if (!field)
1246     returnCode(E_BAD_ARGUMENT);
1247 
1248   CHECKPOS(field->form);
1249   if (((form = field->form) != (FORM *)0)
1250       && Field_Really_Appears(field))
1251     {
1252       if (form->current == field)
1253 	{
1254 	  Synchronize_Buffer(form);
1255 	  Set_Field_Window_Attributes(field, form->w);
1256 	  werase(form->w);
1257 	  wmove(form->w, form->currow, form->curcol);
1258 
1259 	  if ((unsigned)field->opts & O_PUBLIC)
1260 	    {
1261 	      if (Justification_Allowed(field))
1262 		Undo_Justification(field, form->w);
1263 	      else
1264 		Buffer_To_Window(field, form->w);
1265 	    }
1266 	  else
1267 	    {
1268 	      formwin = Get_Form_Window(form);
1269 	      copywin(form->w, formwin,
1270 		      0, 0,
1271 		      field->frow, field->fcol,
1272 		      field->rows - 1, field->cols - 1, 0);
1273 	      wsyncup(formwin);
1274 	      Buffer_To_Window(field, form->w);
1275 	      SetStatus(field, _NEWTOP);	/* fake refresh to paint all */
1276 	      _nc_Refresh_Current_Field(form);
1277 	    }
1278 	}
1279       else
1280 	{
1281 	  res = Display_Field(field);
1282 	}
1283     }
1284   CHECKPOS(form);
1285   returnCode(res);
1286 }
1287 
1288 /*---------------------------------------------------------------------------
1289 |   Facility      :  libnform
1290 |   Function      :  int _nc_Synchronize_Options(FIELD * field,
1291 |                                                Field_Options newopts)
1292 |
1293 |   Description   :  If a fields options have changed, this routine is
1294 |                    called to propagate these changes to the screen and
1295 |                    to really change the behavior of the field.
1296 |
1297 |   Return Values :  E_OK                - success
1298 |                    E_BAD_ARGUMENT      - invalid field pointer
1299 |                    E_CURRENT           - field is the current one
1300 |                    E_SYSTEM_ERROR      - some severe basic error
1301 +--------------------------------------------------------------------------*/
1302 NCURSES_EXPORT(int)
1303 _nc_Synchronize_Options(FIELD *field, Field_Options newopts)
1304 {
1305   Field_Options oldopts;
1306   Field_Options changed_opts;
1307   FORM *form;
1308   int res = E_OK;
1309 
1310   T((T_CALLED("_nc_Synchronize_Options(%p,%#x)"), (void *)field, newopts));
1311 
1312   if (!field)
1313     returnCode(E_BAD_ARGUMENT);
1314 
1315   oldopts = field->opts;
1316   changed_opts = oldopts ^ newopts;
1317   field->opts = newopts;
1318   form = field->form;
1319 
1320   if (form)
1321     {
1322       if (form->status & _POSTED)
1323 	{
1324 	  if (form->current == field)
1325 	    {
1326 	      field->opts = oldopts;
1327 	      returnCode(E_CURRENT);
1328 	    }
1329 	  if (form->curpage == field->page)
1330 	    {
1331 	      if ((unsigned)changed_opts & O_VISIBLE)
1332 		{
1333 		  if ((unsigned)newopts & O_VISIBLE)
1334 		    res = Display_Field(field);
1335 		  else
1336 		    res = Erase_Field(field);
1337 		}
1338 	      else
1339 		{
1340 		  if (((unsigned)changed_opts & O_PUBLIC) &&
1341 		      ((unsigned)newopts & O_VISIBLE))
1342 		    res = Display_Field(field);
1343 		}
1344 	    }
1345 	}
1346     }
1347 
1348   if ((unsigned)changed_opts & O_STATIC)
1349     {
1350       bool single_line_field = Single_Line_Field(field);
1351       int res2 = E_OK;
1352 
1353       if ((unsigned)newopts & O_STATIC)
1354 	{
1355 	  /* the field becomes now static */
1356 	  ClrStatus(field, _MAY_GROW);
1357 	  /* if actually we have no hidden columns, justification may
1358 	     occur again */
1359 	  if (single_line_field &&
1360 	      (field->cols == field->dcols) &&
1361 	      (field->just != NO_JUSTIFICATION) &&
1362 	      Field_Really_Appears(field))
1363 	    {
1364 	      res2 = Display_Field(field);
1365 	    }
1366 	}
1367       else
1368 	{
1369 	  /* field is no longer static */
1370 	  if ((field->maxgrow == 0) ||
1371 	      (single_line_field && (field->dcols < field->maxgrow)) ||
1372 	      (!single_line_field && (field->drows < field->maxgrow)))
1373 	    {
1374 	      SetStatus(field, _MAY_GROW);
1375 	      /* a field with justification now changes its behavior,
1376 	         so we must redisplay it */
1377 	      if (single_line_field &&
1378 		  (field->just != NO_JUSTIFICATION) &&
1379 		  Field_Really_Appears(field))
1380 		{
1381 		  res2 = Display_Field(field);
1382 		}
1383 	    }
1384 	}
1385       if (res2 != E_OK)
1386 	res = res2;
1387     }
1388 
1389   returnCode(res);
1390 }
1391 
1392 /*---------------------------------------------------------------------------
1393 |   Facility      :  libnform
1394 |   Function      :  int _nc_Set_Current_Field(FORM  * form,
1395 |                                              FIELD * newfield)
1396 |
1397 |   Description   :  Make the newfield the new current field.
1398 |
1399 |   Return Values :  E_OK              - success
1400 |                    E_BAD_ARGUMENT    - invalid form or field pointer
1401 |                    E_SYSTEM_ERROR    - some severe basic error
1402 |                    E_NOT_CONNECTED   - no fields are connected to the form
1403 +--------------------------------------------------------------------------*/
1404 NCURSES_EXPORT(int)
1405 _nc_Set_Current_Field(FORM *form, FIELD *newfield)
1406 {
1407   FIELD *field;
1408   WINDOW *new_window;
1409 
1410   T((T_CALLED("_nc_Set_Current_Field(%p,%p)"), (void *)form, (void *)newfield));
1411 
1412   if (!form || !newfield || !form->current || (newfield->form != form))
1413     returnCode(E_BAD_ARGUMENT);
1414 
1415   if ((form->status & _IN_DRIVER))
1416     returnCode(E_BAD_STATE);
1417 
1418   if (!(form->field))
1419     returnCode(E_NOT_CONNECTED);
1420 
1421   field = form->current;
1422 
1423   if ((field != newfield) ||
1424       !(form->status & _POSTED))
1425     {
1426       if ((form->w) &&
1427 	  ((unsigned)field->opts & O_VISIBLE) &&
1428 	  (field->form->curpage == field->page))
1429 	{
1430 	  _nc_Refresh_Current_Field(form);
1431 	  if ((unsigned)field->opts & O_PUBLIC)
1432 	    {
1433 	      if (field->drows > field->rows)
1434 		{
1435 		  if (form->toprow == 0)
1436 		    ClrStatus(field, _NEWTOP);
1437 		  else
1438 		    SetStatus(field, _NEWTOP);
1439 		}
1440 	      else
1441 		{
1442 		  if (Justification_Allowed(field))
1443 		    {
1444 		      Window_To_Buffer(form, field);
1445 		      werase(form->w);
1446 		      Perform_Justification(field, form->w);
1447 		      wsyncup(form->w);
1448 		    }
1449 		}
1450 	    }
1451 	  delwin(form->w);
1452 	  form->w = (WINDOW *)0;
1453 	}
1454 
1455       field = newfield;
1456 
1457       if (Has_Invisible_Parts(field))
1458 	new_window = newpad(field->drows, field->dcols);
1459       else
1460 	new_window = derwin(Get_Form_Window(form),
1461 			    field->rows, field->cols, field->frow, field->fcol);
1462 
1463       if (!new_window)
1464 	returnCode(E_SYSTEM_ERROR);
1465 
1466       form->current = field;
1467 
1468       if (form->w)
1469 	delwin(form->w);
1470       form->w = new_window;
1471 
1472       ClrStatus(form, _WINDOW_MODIFIED);
1473       Set_Field_Window_Attributes(field, form->w);
1474 
1475       if (Has_Invisible_Parts(field))
1476 	{
1477 	  werase(form->w);
1478 	  Buffer_To_Window(field, form->w);
1479 	}
1480       else
1481 	{
1482 	  if (Justification_Allowed(field))
1483 	    {
1484 	      werase(form->w);
1485 	      Undo_Justification(field, form->w);
1486 	      wsyncup(form->w);
1487 	    }
1488 	}
1489 
1490       untouchwin(form->w);
1491     }
1492 
1493   form->currow = form->curcol = form->toprow = form->begincol = 0;
1494   returnCode(E_OK);
1495 }
1496 
1497 /*----------------------------------------------------------------------------
1498   Intra-Field Navigation routines
1499   --------------------------------------------------------------------------*/
1500 
1501 /*---------------------------------------------------------------------------
1502 |   Facility      :  libnform
1503 |   Function      :  static int IFN_Next_Character(FORM * form)
1504 |
1505 |   Description   :  Move to the next character in the field. In a multi-line
1506 |                    field this wraps at the end of the line.
1507 |
1508 |   Return Values :  E_OK                - success
1509 |                    E_REQUEST_DENIED    - at the rightmost position
1510 +--------------------------------------------------------------------------*/
1511 static int
1512 IFN_Next_Character(FORM *form)
1513 {
1514   FIELD *field = form->current;
1515   int step = myWCWIDTH(form->w, form->currow, form->curcol);
1516 
1517   T((T_CALLED("IFN_Next_Character(%p)"), (void *)form));
1518   if ((form->curcol += step) == field->dcols)
1519     {
1520       if ((++(form->currow)) == field->drows)
1521 	{
1522 #if GROW_IF_NAVIGATE
1523 	  if (!Single_Line_Field(field) && Field_Grown(field, 1))
1524 	    {
1525 	      form->curcol = 0;
1526 	      returnCode(E_OK);
1527 	    }
1528 #endif
1529 	  form->currow--;
1530 #if GROW_IF_NAVIGATE
1531 	  if (Single_Line_Field(field) && Field_Grown(field, 1))
1532 	    returnCode(E_OK);
1533 #endif
1534 	  form->curcol -= step;
1535 	  returnCode(E_REQUEST_DENIED);
1536 	}
1537       form->curcol = 0;
1538     }
1539   returnCode(E_OK);
1540 }
1541 
1542 /*---------------------------------------------------------------------------
1543 |   Facility      :  libnform
1544 |   Function      :  static int IFN_Previous_Character(FORM * form)
1545 |
1546 |   Description   :  Move to the previous character in the field. In a
1547 |                    multi-line field this wraps and the beginning of the
1548 |                    line.
1549 |
1550 |   Return Values :  E_OK                - success
1551 |                    E_REQUEST_DENIED    - at the leftmost position
1552 +--------------------------------------------------------------------------*/
1553 static int
1554 IFN_Previous_Character(FORM *form)
1555 {
1556   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1557   int oldcol = form->curcol;
1558 
1559   T((T_CALLED("IFN_Previous_Character(%p)"), (void *)form));
1560   if ((form->curcol -= amount) < 0)
1561     {
1562       if ((--(form->currow)) < 0)
1563 	{
1564 	  form->currow++;
1565 	  form->curcol = oldcol;
1566 	  returnCode(E_REQUEST_DENIED);
1567 	}
1568       form->curcol = form->current->dcols - 1;
1569     }
1570   returnCode(E_OK);
1571 }
1572 
1573 /*---------------------------------------------------------------------------
1574 |   Facility      :  libnform
1575 |   Function      :  static int IFN_Next_Line(FORM * form)
1576 |
1577 |   Description   :  Move to the beginning of the next line in the field
1578 |
1579 |   Return Values :  E_OK                - success
1580 |                    E_REQUEST_DENIED    - at the last line
1581 +--------------------------------------------------------------------------*/
1582 static int
1583 IFN_Next_Line(FORM *form)
1584 {
1585   FIELD *field = form->current;
1586 
1587   T((T_CALLED("IFN_Next_Line(%p)"), (void *)form));
1588   if ((++(form->currow)) == field->drows)
1589     {
1590 #if GROW_IF_NAVIGATE
1591       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1592 	returnCode(E_OK);
1593 #endif
1594       form->currow--;
1595       returnCode(E_REQUEST_DENIED);
1596     }
1597   form->curcol = 0;
1598   returnCode(E_OK);
1599 }
1600 
1601 /*---------------------------------------------------------------------------
1602 |   Facility      :  libnform
1603 |   Function      :  static int IFN_Previous_Line(FORM * form)
1604 |
1605 |   Description   :  Move to the beginning of the previous line in the field
1606 |
1607 |   Return Values :  E_OK                - success
1608 |                    E_REQUEST_DENIED    - at the first line
1609 +--------------------------------------------------------------------------*/
1610 static int
1611 IFN_Previous_Line(FORM *form)
1612 {
1613   T((T_CALLED("IFN_Previous_Line(%p)"), (void *)form));
1614   if ((--(form->currow)) < 0)
1615     {
1616       form->currow++;
1617       returnCode(E_REQUEST_DENIED);
1618     }
1619   form->curcol = 0;
1620   returnCode(E_OK);
1621 }
1622 
1623 /*---------------------------------------------------------------------------
1624 |   Facility      :  libnform
1625 |   Function      :  static int IFN_Next_Word(FORM * form)
1626 |
1627 |   Description   :  Move to the beginning of the next word in the field.
1628 |
1629 |   Return Values :  E_OK             - success
1630 |                    E_REQUEST_DENIED - there is no next word
1631 +--------------------------------------------------------------------------*/
1632 static int
1633 IFN_Next_Word(FORM *form)
1634 {
1635   FIELD *field = form->current;
1636   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1637   FIELD_CELL *s;
1638   FIELD_CELL *t;
1639 
1640   T((T_CALLED("IFN_Next_Word(%p)"), (void *)form));
1641 
1642   /* We really need access to the data, so we have to synchronize */
1643   Synchronize_Buffer(form);
1644 
1645   /* Go to the first whitespace after the current position (including
1646      current position). This is then the starting point to look for the
1647      next non-blank data */
1648   s = Get_First_Whitespace_Character(bp, Buffer_Length(field) -
1649 				     (int)(bp - field->buf));
1650 
1651   /* Find the start of the next word */
1652   t = Get_Start_Of_Data(s, Buffer_Length(field) -
1653 			(int)(s - field->buf));
1654 #if !FRIENDLY_PREV_NEXT_WORD
1655   if (s == t)
1656     returnCode(E_REQUEST_DENIED);
1657   else
1658 #endif
1659     {
1660       Adjust_Cursor_Position(form, t);
1661       returnCode(E_OK);
1662     }
1663 }
1664 
1665 /*---------------------------------------------------------------------------
1666 |   Facility      :  libnform
1667 |   Function      :  static int IFN_Previous_Word(FORM * form)
1668 |
1669 |   Description   :  Move to the beginning of the previous word in the field.
1670 |
1671 |   Return Values :  E_OK             - success
1672 |                    E_REQUEST_DENIED - there is no previous word
1673 +--------------------------------------------------------------------------*/
1674 static int
1675 IFN_Previous_Word(FORM *form)
1676 {
1677   FIELD *field = form->current;
1678   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1679   FIELD_CELL *s;
1680   FIELD_CELL *t;
1681   bool again = FALSE;
1682 
1683   T((T_CALLED("IFN_Previous_Word(%p)"), (void *)form));
1684 
1685   /* We really need access to the data, so we have to synchronize */
1686   Synchronize_Buffer(form);
1687 
1688   s = After_End_Of_Data(field->buf, (int)(bp - field->buf));
1689   /* s points now right after the last non-blank in the buffer before bp.
1690      If bp was in a word, s equals bp. In this case we must find the last
1691      whitespace in the buffer before bp and repeat the game to really find
1692      the previous word! */
1693   if (s == bp)
1694     again = TRUE;
1695 
1696   /* And next call now goes backward to look for the last whitespace
1697      before that, pointing right after this, so it points to the begin
1698      of the previous word.
1699    */
1700   t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1701 #if !FRIENDLY_PREV_NEXT_WORD
1702   if (s == t)
1703     returnCode(E_REQUEST_DENIED);
1704 #endif
1705   if (again)
1706     {
1707       /* and do it again, replacing bp by t */
1708       s = After_End_Of_Data(field->buf, (int)(t - field->buf));
1709       t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1710 #if !FRIENDLY_PREV_NEXT_WORD
1711       if (s == t)
1712 	returnCode(E_REQUEST_DENIED);
1713 #endif
1714     }
1715   Adjust_Cursor_Position(form, t);
1716   returnCode(E_OK);
1717 }
1718 
1719 /*---------------------------------------------------------------------------
1720 |   Facility      :  libnform
1721 |   Function      :  static int IFN_Beginning_Of_Field(FORM * form)
1722 |
1723 |   Description   :  Place the cursor at the first non-pad character in
1724 |                    the field.
1725 |
1726 |   Return Values :  E_OK             - success
1727 +--------------------------------------------------------------------------*/
1728 static int
1729 IFN_Beginning_Of_Field(FORM *form)
1730 {
1731   FIELD *field = form->current;
1732 
1733   T((T_CALLED("IFN_Beginning_Of_Field(%p)"), (void *)form));
1734   Synchronize_Buffer(form);
1735   Adjust_Cursor_Position(form,
1736 			 Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1737   returnCode(E_OK);
1738 }
1739 
1740 /*---------------------------------------------------------------------------
1741 |   Facility      :  libnform
1742 |   Function      :  static int IFN_End_Of_Field(FORM * form)
1743 |
1744 |   Description   :  Place the cursor after the last non-pad character in
1745 |                    the field. If the field occupies the last position in
1746 |                    the buffer, the cursor is positioned on the last
1747 |                    character.
1748 |
1749 |   Return Values :  E_OK              - success
1750 +--------------------------------------------------------------------------*/
1751 static int
1752 IFN_End_Of_Field(FORM *form)
1753 {
1754   FIELD *field = form->current;
1755   FIELD_CELL *pos;
1756 
1757   T((T_CALLED("IFN_End_Of_Field(%p)"), (void *)form));
1758   Synchronize_Buffer(form);
1759   pos = After_End_Of_Data(field->buf, Buffer_Length(field));
1760   if (pos == (field->buf + Buffer_Length(field)))
1761     pos--;
1762   Adjust_Cursor_Position(form, pos);
1763   returnCode(E_OK);
1764 }
1765 
1766 /*---------------------------------------------------------------------------
1767 |   Facility      :  libnform
1768 |   Function      :  static int IFN_Beginning_Of_Line(FORM * form)
1769 |
1770 |   Description   :  Place the cursor on the first non-pad character in
1771 |                    the current line of the field.
1772 |
1773 |   Return Values :  E_OK         - success
1774 +--------------------------------------------------------------------------*/
1775 static int
1776 IFN_Beginning_Of_Line(FORM *form)
1777 {
1778   FIELD *field = form->current;
1779 
1780   T((T_CALLED("IFN_Beginning_Of_Line(%p)"), (void *)form));
1781   Synchronize_Buffer(form);
1782   Adjust_Cursor_Position(form,
1783 			 Get_Start_Of_Data(Address_Of_Current_Row_In_Buffer(form),
1784 					   field->dcols));
1785   returnCode(E_OK);
1786 }
1787 
1788 /*---------------------------------------------------------------------------
1789 |   Facility      :  libnform
1790 |   Function      :  static int IFN_End_Of_Line(FORM * form)
1791 |
1792 |   Description   :  Place the cursor after the last non-pad character in the
1793 |                    current line of the field. If the field occupies the
1794 |                    last column in the line, the cursor is positioned on the
1795 |                    last character of the line.
1796 |
1797 |   Return Values :  E_OK        - success
1798 +--------------------------------------------------------------------------*/
1799 static int
1800 IFN_End_Of_Line(FORM *form)
1801 {
1802   FIELD *field = form->current;
1803   FIELD_CELL *pos;
1804   FIELD_CELL *bp;
1805 
1806   T((T_CALLED("IFN_End_Of_Line(%p)"), (void *)form));
1807   Synchronize_Buffer(form);
1808   bp = Address_Of_Current_Row_In_Buffer(form);
1809   pos = After_End_Of_Data(bp, field->dcols);
1810   if (pos == (bp + field->dcols))
1811     pos--;
1812   Adjust_Cursor_Position(form, pos);
1813   returnCode(E_OK);
1814 }
1815 
1816 /*---------------------------------------------------------------------------
1817 |   Facility      :  libnform
1818 |   Function      :  static int IFN_Left_Character(FORM * form)
1819 |
1820 |   Description   :  Move one character to the left in the current line.
1821 |                    This doesn't cycle.
1822 |
1823 |   Return Values :  E_OK             - success
1824 |                    E_REQUEST_DENIED - already in first column
1825 +--------------------------------------------------------------------------*/
1826 static int
1827 IFN_Left_Character(FORM *form)
1828 {
1829   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1830   int oldcol = form->curcol;
1831 
1832   T((T_CALLED("IFN_Left_Character(%p)"), (void *)form));
1833   if ((form->curcol -= amount) < 0)
1834     {
1835       form->curcol = oldcol;
1836       returnCode(E_REQUEST_DENIED);
1837     }
1838   returnCode(E_OK);
1839 }
1840 
1841 /*---------------------------------------------------------------------------
1842 |   Facility      :  libnform
1843 |   Function      :  static int IFN_Right_Character(FORM * form)
1844 |
1845 |   Description   :  Move one character to the right in the current line.
1846 |                    This doesn't cycle.
1847 |
1848 |   Return Values :  E_OK              - success
1849 |                    E_REQUEST_DENIED  - already in last column
1850 +--------------------------------------------------------------------------*/
1851 static int
1852 IFN_Right_Character(FORM *form)
1853 {
1854   int amount = myWCWIDTH(form->w, form->currow, form->curcol);
1855   int oldcol = form->curcol;
1856 
1857   T((T_CALLED("IFN_Right_Character(%p)"), (void *)form));
1858   if ((form->curcol += amount) >= form->current->dcols)
1859     {
1860 #if GROW_IF_NAVIGATE
1861       FIELD *field = form->current;
1862 
1863       if (Single_Line_Field(field) && Field_Grown(field, 1))
1864 	returnCode(E_OK);
1865 #endif
1866       form->curcol = oldcol;
1867       returnCode(E_REQUEST_DENIED);
1868     }
1869   returnCode(E_OK);
1870 }
1871 
1872 /*---------------------------------------------------------------------------
1873 |   Facility      :  libnform
1874 |   Function      :  static int IFN_Up_Character(FORM * form)
1875 |
1876 |   Description   :  Move one line up. This doesn't cycle through the lines
1877 |                    of the field.
1878 |
1879 |   Return Values :  E_OK              - success
1880 |                    E_REQUEST_DENIED  - already in last column
1881 +--------------------------------------------------------------------------*/
1882 static int
1883 IFN_Up_Character(FORM *form)
1884 {
1885   T((T_CALLED("IFN_Up_Character(%p)"), (void *)form));
1886   if ((--(form->currow)) < 0)
1887     {
1888       form->currow++;
1889       returnCode(E_REQUEST_DENIED);
1890     }
1891   returnCode(E_OK);
1892 }
1893 
1894 /*---------------------------------------------------------------------------
1895 |   Facility      :  libnform
1896 |   Function      :  static int IFN_Down_Character(FORM * form)
1897 |
1898 |   Description   :  Move one line down. This doesn't cycle through the
1899 |                    lines of the field.
1900 |
1901 |   Return Values :  E_OK              - success
1902 |                    E_REQUEST_DENIED  - already in last column
1903 +--------------------------------------------------------------------------*/
1904 static int
1905 IFN_Down_Character(FORM *form)
1906 {
1907   FIELD *field = form->current;
1908 
1909   T((T_CALLED("IFN_Down_Character(%p)"), (void *)form));
1910   if ((++(form->currow)) == field->drows)
1911     {
1912 #if GROW_IF_NAVIGATE
1913       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1914 	returnCode(E_OK);
1915 #endif
1916       --(form->currow);
1917       returnCode(E_REQUEST_DENIED);
1918     }
1919   returnCode(E_OK);
1920 }
1921 /*----------------------------------------------------------------------------
1922   END of Intra-Field Navigation routines
1923   --------------------------------------------------------------------------*/
1924 
1925 /*----------------------------------------------------------------------------
1926   Vertical scrolling helper routines
1927   --------------------------------------------------------------------------*/
1928 
1929 /*---------------------------------------------------------------------------
1930 |   Facility      :  libnform
1931 |   Function      :  static int VSC_Generic(FORM *form, int nlines)
1932 |
1933 |   Description   :  Scroll multi-line field forward (nlines>0) or
1934 |                    backward (nlines<0) this many lines.
1935 |
1936 |   Return Values :  E_OK              - success
1937 |                    E_REQUEST_DENIED  - can't scroll
1938 +--------------------------------------------------------------------------*/
1939 static int
1940 VSC_Generic(FORM *form, int nlines)
1941 {
1942   FIELD *field = form->current;
1943   int res = E_REQUEST_DENIED;
1944   int rows_to_go = (nlines > 0 ? nlines : -nlines);
1945 
1946   if (nlines > 0)
1947     {
1948       if ((rows_to_go + form->toprow) > (field->drows - field->rows))
1949 	rows_to_go = (field->drows - field->rows - form->toprow);
1950 
1951       if (rows_to_go > 0)
1952 	{
1953 	  form->currow += rows_to_go;
1954 	  form->toprow += rows_to_go;
1955 	  res = E_OK;
1956 	}
1957     }
1958   else
1959     {
1960       if (rows_to_go > form->toprow)
1961 	rows_to_go = form->toprow;
1962 
1963       if (rows_to_go > 0)
1964 	{
1965 	  form->currow -= rows_to_go;
1966 	  form->toprow -= rows_to_go;
1967 	  res = E_OK;
1968 	}
1969     }
1970   return (res);
1971 }
1972 /*----------------------------------------------------------------------------
1973   End of Vertical scrolling helper routines
1974   --------------------------------------------------------------------------*/
1975 
1976 /*----------------------------------------------------------------------------
1977   Vertical scrolling routines
1978   --------------------------------------------------------------------------*/
1979 
1980 /*---------------------------------------------------------------------------
1981 |   Facility      :  libnform
1982 |   Function      :  static int Vertical_Scrolling(
1983 |                                           int (* const fct) (FORM *),
1984 |                                           FORM * form)
1985 |
1986 |   Description   :  Performs the generic vertical scrolling routines.
1987 |                    This has to check for a multi-line field and to set
1988 |                    the _NEWTOP flag if scrolling really occurred.
1989 |
1990 |   Return Values :  Propagated error code from low-level driver calls
1991 +--------------------------------------------------------------------------*/
1992 static int
1993 Vertical_Scrolling(int (*const fct) (FORM *), FORM *form)
1994 {
1995   int res = E_REQUEST_DENIED;
1996 
1997   if (!Single_Line_Field(form->current))
1998     {
1999       res = fct(form);
2000       if (res == E_OK)
2001 	SetStatus(form, _NEWTOP);
2002     }
2003   return (res);
2004 }
2005 
2006 /*---------------------------------------------------------------------------
2007 |   Facility      :  libnform
2008 |   Function      :  static int VSC_Scroll_Line_Forward(FORM * form)
2009 |
2010 |   Description   :  Scroll multi-line field forward a line
2011 |
2012 |   Return Values :  E_OK                - success
2013 |                    E_REQUEST_DENIED    - no data ahead
2014 +--------------------------------------------------------------------------*/
2015 static int
2016 VSC_Scroll_Line_Forward(FORM *form)
2017 {
2018   T((T_CALLED("VSC_Scroll_Line_Forward(%p)"), (void *)form));
2019   returnCode(VSC_Generic(form, 1));
2020 }
2021 
2022 /*---------------------------------------------------------------------------
2023 |   Facility      :  libnform
2024 |   Function      :  static int VSC_Scroll_Line_Backward(FORM * form)
2025 |
2026 |   Description   :  Scroll multi-line field backward a line
2027 |
2028 |   Return Values :  E_OK                - success
2029 |                    E_REQUEST_DENIED    - no data behind
2030 +--------------------------------------------------------------------------*/
2031 static int
2032 VSC_Scroll_Line_Backward(FORM *form)
2033 {
2034   T((T_CALLED("VSC_Scroll_Line_Backward(%p)"), (void *)form));
2035   returnCode(VSC_Generic(form, -1));
2036 }
2037 
2038 /*---------------------------------------------------------------------------
2039 |   Facility      :  libnform
2040 |   Function      :  static int VSC_Scroll_Page_Forward(FORM * form)
2041 |
2042 |   Description   :  Scroll a multi-line field forward a page
2043 |
2044 |   Return Values :  E_OK              - success
2045 |                    E_REQUEST_DENIED  - no data ahead
2046 +--------------------------------------------------------------------------*/
2047 static int
2048 VSC_Scroll_Page_Forward(FORM *form)
2049 {
2050   T((T_CALLED("VSC_Scroll_Page_Forward(%p)"), (void *)form));
2051   returnCode(VSC_Generic(form, form->current->rows));
2052 }
2053 
2054 /*---------------------------------------------------------------------------
2055 |   Facility      :  libnform
2056 |   Function      :  static int VSC_Scroll_Half_Page_Forward(FORM * form)
2057 |
2058 |   Description   :  Scroll a multi-line field forward half a page
2059 |
2060 |   Return Values :  E_OK              - success
2061 |                    E_REQUEST_DENIED  - no data ahead
2062 +--------------------------------------------------------------------------*/
2063 static int
2064 VSC_Scroll_Half_Page_Forward(FORM *form)
2065 {
2066   T((T_CALLED("VSC_Scroll_Half_Page_Forward(%p)"), (void *)form));
2067   returnCode(VSC_Generic(form, (form->current->rows + 1) / 2));
2068 }
2069 
2070 /*---------------------------------------------------------------------------
2071 |   Facility      :  libnform
2072 |   Function      :  static int VSC_Scroll_Page_Backward(FORM * form)
2073 |
2074 |   Description   :  Scroll a multi-line field backward a page
2075 |
2076 |   Return Values :  E_OK              - success
2077 |                    E_REQUEST_DENIED  - no data behind
2078 +--------------------------------------------------------------------------*/
2079 static int
2080 VSC_Scroll_Page_Backward(FORM *form)
2081 {
2082   T((T_CALLED("VSC_Scroll_Page_Backward(%p)"), (void *)form));
2083   returnCode(VSC_Generic(form, -(form->current->rows)));
2084 }
2085 
2086 /*---------------------------------------------------------------------------
2087 |   Facility      :  libnform
2088 |   Function      :  static int VSC_Scroll_Half_Page_Backward(FORM * form)
2089 |
2090 |   Description   :  Scroll a multi-line field backward half a page
2091 |
2092 |   Return Values :  E_OK              - success
2093 |                    E_REQUEST_DENIED  - no data behind
2094 +--------------------------------------------------------------------------*/
2095 static int
2096 VSC_Scroll_Half_Page_Backward(FORM *form)
2097 {
2098   T((T_CALLED("VSC_Scroll_Half_Page_Backward(%p)"), (void *)form));
2099   returnCode(VSC_Generic(form, -((form->current->rows + 1) / 2)));
2100 }
2101 /*----------------------------------------------------------------------------
2102   End of Vertical scrolling routines
2103   --------------------------------------------------------------------------*/
2104 
2105 /*----------------------------------------------------------------------------
2106   Horizontal scrolling helper routines
2107   --------------------------------------------------------------------------*/
2108 
2109 /*---------------------------------------------------------------------------
2110 |   Facility      :  libnform
2111 |   Function      :  static int HSC_Generic(FORM *form, int ncolumns)
2112 |
2113 |   Description   :  Scroll single-line field forward (ncolumns>0) or
2114 |                    backward (ncolumns<0) this many columns.
2115 |
2116 |   Return Values :  E_OK              - success
2117 |                    E_REQUEST_DENIED  - can't scroll
2118 +--------------------------------------------------------------------------*/
2119 static int
2120 HSC_Generic(FORM *form, int ncolumns)
2121 {
2122   FIELD *field = form->current;
2123   int res = E_REQUEST_DENIED;
2124   int cols_to_go = (ncolumns > 0 ? ncolumns : -ncolumns);
2125 
2126   if (ncolumns > 0)
2127     {
2128       if ((cols_to_go + form->begincol) > (field->dcols - field->cols))
2129 	cols_to_go = field->dcols - field->cols - form->begincol;
2130 
2131       if (cols_to_go > 0)
2132 	{
2133 	  form->curcol += cols_to_go;
2134 	  form->begincol += cols_to_go;
2135 	  res = E_OK;
2136 	}
2137     }
2138   else
2139     {
2140       if (cols_to_go > form->begincol)
2141 	cols_to_go = form->begincol;
2142 
2143       if (cols_to_go > 0)
2144 	{
2145 	  form->curcol -= cols_to_go;
2146 	  form->begincol -= cols_to_go;
2147 	  res = E_OK;
2148 	}
2149     }
2150   return (res);
2151 }
2152 /*----------------------------------------------------------------------------
2153   End of Horizontal scrolling helper routines
2154   --------------------------------------------------------------------------*/
2155 
2156 /*----------------------------------------------------------------------------
2157   Horizontal scrolling routines
2158   --------------------------------------------------------------------------*/
2159 
2160 /*---------------------------------------------------------------------------
2161 |   Facility      :  libnform
2162 |   Function      :  static int Horizontal_Scrolling(
2163 |                                          int (* const fct) (FORM *),
2164 |                                          FORM * form)
2165 |
2166 |   Description   :  Performs the generic horizontal scrolling routines.
2167 |                    This has to check for a single-line field.
2168 |
2169 |   Return Values :  Propagated error code from low-level driver calls
2170 +--------------------------------------------------------------------------*/
2171 static int
2172 Horizontal_Scrolling(int (*const fct) (FORM *), FORM *form)
2173 {
2174   if (Single_Line_Field(form->current))
2175     return fct(form);
2176   else
2177     return (E_REQUEST_DENIED);
2178 }
2179 
2180 /*---------------------------------------------------------------------------
2181 |   Facility      :  libnform
2182 |   Function      :  static int HSC_Scroll_Char_Forward(FORM * form)
2183 |
2184 |   Description   :  Scroll single-line field forward a character
2185 |
2186 |   Return Values :  E_OK                - success
2187 |                    E_REQUEST_DENIED    - no data ahead
2188 +--------------------------------------------------------------------------*/
2189 static int
2190 HSC_Scroll_Char_Forward(FORM *form)
2191 {
2192   T((T_CALLED("HSC_Scroll_Char_Forward(%p)"), (void *)form));
2193   returnCode(HSC_Generic(form, 1));
2194 }
2195 
2196 /*---------------------------------------------------------------------------
2197 |   Facility      :  libnform
2198 |   Function      :  static int HSC_Scroll_Char_Backward(FORM * form)
2199 |
2200 |   Description   :  Scroll single-line field backward a character
2201 |
2202 |   Return Values :  E_OK                - success
2203 |                    E_REQUEST_DENIED    - no data behind
2204 +--------------------------------------------------------------------------*/
2205 static int
2206 HSC_Scroll_Char_Backward(FORM *form)
2207 {
2208   T((T_CALLED("HSC_Scroll_Char_Backward(%p)"), (void *)form));
2209   returnCode(HSC_Generic(form, -1));
2210 }
2211 
2212 /*---------------------------------------------------------------------------
2213 |   Facility      :  libnform
2214 |   Function      :  static int HSC_Horizontal_Line_Forward(FORM* form)
2215 |
2216 |   Description   :  Scroll single-line field forward a line
2217 |
2218 |   Return Values :  E_OK                - success
2219 |                    E_REQUEST_DENIED    - no data ahead
2220 +--------------------------------------------------------------------------*/
2221 static int
2222 HSC_Horizontal_Line_Forward(FORM *form)
2223 {
2224   T((T_CALLED("HSC_Horizontal_Line_Forward(%p)"), (void *)form));
2225   returnCode(HSC_Generic(form, form->current->cols));
2226 }
2227 
2228 /*---------------------------------------------------------------------------
2229 |   Facility      :  libnform
2230 |   Function      :  static int HSC_Horizontal_Half_Line_Forward(FORM* form)
2231 |
2232 |   Description   :  Scroll single-line field forward half a line
2233 |
2234 |   Return Values :  E_OK               - success
2235 |                    E_REQUEST_DENIED   - no data ahead
2236 +--------------------------------------------------------------------------*/
2237 static int
2238 HSC_Horizontal_Half_Line_Forward(FORM *form)
2239 {
2240   T((T_CALLED("HSC_Horizontal_Half_Line_Forward(%p)"), (void *)form));
2241   returnCode(HSC_Generic(form, (form->current->cols + 1) / 2));
2242 }
2243 
2244 /*---------------------------------------------------------------------------
2245 |   Facility      :  libnform
2246 |   Function      :  static int HSC_Horizontal_Line_Backward(FORM* form)
2247 |
2248 |   Description   :  Scroll single-line field backward a line
2249 |
2250 |   Return Values :  E_OK                - success
2251 |                    E_REQUEST_DENIED    - no data behind
2252 +--------------------------------------------------------------------------*/
2253 static int
2254 HSC_Horizontal_Line_Backward(FORM *form)
2255 {
2256   T((T_CALLED("HSC_Horizontal_Line_Backward(%p)"), (void *)form));
2257   returnCode(HSC_Generic(form, -(form->current->cols)));
2258 }
2259 
2260 /*---------------------------------------------------------------------------
2261 |   Facility      :  libnform
2262 |   Function      :  static int HSC_Horizontal_Half_Line_Backward(FORM* form)
2263 |
2264 |   Description   :  Scroll single-line field backward half a line
2265 |
2266 |   Return Values :  E_OK                - success
2267 |                    E_REQUEST_DENIED    - no data behind
2268 +--------------------------------------------------------------------------*/
2269 static int
2270 HSC_Horizontal_Half_Line_Backward(FORM *form)
2271 {
2272   T((T_CALLED("HSC_Horizontal_Half_Line_Backward(%p)"), (void *)form));
2273   returnCode(HSC_Generic(form, -((form->current->cols + 1) / 2)));
2274 }
2275 
2276 /*----------------------------------------------------------------------------
2277   End of Horizontal scrolling routines
2278   --------------------------------------------------------------------------*/
2279 
2280 /*----------------------------------------------------------------------------
2281   Helper routines for Field Editing
2282   --------------------------------------------------------------------------*/
2283 
2284 /*---------------------------------------------------------------------------
2285 |   Facility      :  libnform
2286 |   Function      :  static bool Is_There_Room_For_A_Line(FORM * form)
2287 |
2288 |   Description   :  Check whether or not there is enough room in the
2289 |                    buffer to enter a whole line.
2290 |
2291 |   Return Values :  TRUE   - there is enough space
2292 |                    FALSE  - there is not enough space
2293 +--------------------------------------------------------------------------*/
2294 NCURSES_INLINE static bool
2295 Is_There_Room_For_A_Line(FORM *form)
2296 {
2297   FIELD *field = form->current;
2298   FIELD_CELL *begin_of_last_line, *s;
2299 
2300   Synchronize_Buffer(form);
2301   begin_of_last_line = Address_Of_Row_In_Buffer(field, (field->drows - 1));
2302   s = After_End_Of_Data(begin_of_last_line, field->dcols);
2303   return ((s == begin_of_last_line) ? TRUE : FALSE);
2304 }
2305 
2306 /*---------------------------------------------------------------------------
2307 |   Facility      :  libnform
2308 |   Function      :  static bool Is_There_Room_For_A_Char_In_Line(FORM * form)
2309 |
2310 |   Description   :  Checks whether or not there is room for a new character
2311 |                    in the current line.
2312 |
2313 |   Return Values :  TRUE    - there is room
2314 |                    FALSE   - there is not enough room (line full)
2315 +--------------------------------------------------------------------------*/
2316 NCURSES_INLINE static bool
2317 Is_There_Room_For_A_Char_In_Line(FORM *form)
2318 {
2319   int last_char_in_line;
2320 
2321   wmove(form->w, form->currow, form->current->dcols - 1);
2322   last_char_in_line = (int)(winch(form->w) & A_CHARTEXT);
2323   wmove(form->w, form->currow, form->curcol);
2324   return (((last_char_in_line == form->current->pad) ||
2325 	   is_blank(last_char_in_line)) ? TRUE : FALSE);
2326 }
2327 
2328 #define There_Is_No_Room_For_A_Char_In_Line(f) \
2329   !Is_There_Room_For_A_Char_In_Line(f)
2330 
2331 /*---------------------------------------------------------------------------
2332 |   Facility      :  libnform
2333 |   Function      :  static int Insert_String(
2334 |                                             FORM * form,
2335 |                                             int row,
2336 |                                             char *txt,
2337 |                                             int  len )
2338 |
2339 |   Description   :  Insert the 'len' characters beginning at pointer 'txt'
2340 |                    into the 'row' of the 'form'. The insertion occurs
2341 |                    on the beginning of the row, all other characters are
2342 |                    moved to the right. After the text a pad character will
2343 |                    be inserted to separate the text from the rest. If
2344 |                    necessary the insertion moves characters on the next
2345 |                    line to make place for the requested insertion string.
2346 |
2347 |   Return Values :  E_OK              - success
2348 |                    E_REQUEST_DENIED  -
2349 |                    E_SYSTEM_ERROR    - system error
2350 +--------------------------------------------------------------------------*/
2351 static int
2352 Insert_String(FORM *form, int row, FIELD_CELL *txt, int len)
2353 {
2354   FIELD *field = form->current;
2355   FIELD_CELL *bp = Address_Of_Row_In_Buffer(field, row);
2356   int datalen = (int)(After_End_Of_Data(bp, field->dcols) - bp);
2357   int freelen = field->dcols - datalen;
2358   int requiredlen = len + 1;
2359   FIELD_CELL *split;
2360   int result = E_REQUEST_DENIED;
2361 
2362   if (freelen >= requiredlen)
2363     {
2364       wmove(form->w, row, 0);
2365       myINSNSTR(form->w, txt, len);
2366       wmove(form->w, row, len);
2367       myINSNSTR(form->w, &myBLANK, 1);
2368       return E_OK;
2369     }
2370   else
2371     {
2372       /* we have to move characters on the next line. If we are on the
2373          last line this may work, if the field is growable */
2374       if ((row == (field->drows - 1)) && Growable(field))
2375 	{
2376 	  if (!Field_Grown(field, 1))
2377 	    return (E_SYSTEM_ERROR);
2378 	  /* !!!Side-Effect : might be changed due to growth!!! */
2379 	  bp = Address_Of_Row_In_Buffer(field, row);
2380 	}
2381 
2382       if (row < (field->drows - 1))
2383 	{
2384 	  split =
2385 	    After_Last_Whitespace_Character(bp,
2386 					    (int)(Get_Start_Of_Data(bp
2387 								    + field->dcols
2388 								    - requiredlen,
2389 								    requiredlen)
2390 						  - bp));
2391 	  /* split points now to the first character of the portion of the
2392 	     line that must be moved to the next line */
2393 	  datalen = (int)(split - bp);	/* + freelen has to stay on this line   */
2394 	  freelen = field->dcols - (datalen + freelen);		/* for the next line */
2395 
2396 	  if ((result = Insert_String(form, row + 1, split, freelen)) == E_OK)
2397 	    {
2398 	      wmove(form->w, row, datalen);
2399 	      wclrtoeol(form->w);
2400 	      wmove(form->w, row, 0);
2401 	      myINSNSTR(form->w, txt, len);
2402 	      wmove(form->w, row, len);
2403 	      myINSNSTR(form->w, &myBLANK, 1);
2404 	      return E_OK;
2405 	    }
2406 	}
2407       return (result);
2408     }
2409 }
2410 
2411 /*---------------------------------------------------------------------------
2412 |   Facility      :  libnform
2413 |   Function      :  static int Wrapping_Not_Necessary_Or_Wrapping_Ok(
2414 |                                             FORM * form)
2415 |
2416 |   Description   :  If a character has been entered into a field, it may
2417 |                    be that wrapping has to occur. This routine checks
2418 |                    whether or not wrapping is required and if so, performs
2419 |                    the wrapping.
2420 |
2421 |   Return Values :  E_OK              - no wrapping required or wrapping
2422 |                                        was successful
2423 |                    E_REQUEST_DENIED  -
2424 |                    E_SYSTEM_ERROR    - some system error
2425 +--------------------------------------------------------------------------*/
2426 static int
2427 Wrapping_Not_Necessary_Or_Wrapping_Ok(FORM *form)
2428 {
2429   FIELD *field = form->current;
2430   int result = E_REQUEST_DENIED;
2431   bool Last_Row = ((field->drows - 1) == form->currow);
2432 
2433   if (((unsigned)field->opts & O_WRAP) &&	/* wrapping wanted     */
2434       (!Single_Line_Field(field)) &&	/* must be multi-line  */
2435       (There_Is_No_Room_For_A_Char_In_Line(form)) &&	/* line is full        */
2436       (!Last_Row || Growable(field)))	/* there are more lines */
2437     {
2438       FIELD_CELL *bp;
2439       FIELD_CELL *split;
2440       int chars_to_be_wrapped;
2441       int chars_to_remain_on_line;
2442 
2443       if (Last_Row)
2444 	{
2445 	  /* the above logic already ensures, that in this case the field
2446 	     is growable */
2447 	  if (!Field_Grown(field, 1))
2448 	    return E_SYSTEM_ERROR;
2449 	}
2450       bp = Address_Of_Current_Row_In_Buffer(form);
2451       Window_To_Buffer(form, field);
2452       split = After_Last_Whitespace_Character(bp, field->dcols);
2453       /* split points to the first character of the sequence to be brought
2454          on the next line */
2455       chars_to_remain_on_line = (int)(split - bp);
2456       chars_to_be_wrapped = field->dcols - chars_to_remain_on_line;
2457       if (chars_to_remain_on_line > 0)
2458 	{
2459 	  if ((result = Insert_String(form, form->currow + 1, split,
2460 				      chars_to_be_wrapped)) == E_OK)
2461 	    {
2462 	      wmove(form->w, form->currow, chars_to_remain_on_line);
2463 	      wclrtoeol(form->w);
2464 	      if (form->curcol >= chars_to_remain_on_line)
2465 		{
2466 		  form->currow++;
2467 		  form->curcol -= chars_to_remain_on_line;
2468 		}
2469 	      return E_OK;
2470 	    }
2471 	}
2472       else
2473 	return E_OK;
2474       if (result != E_OK)
2475 	{
2476 	  DeleteChar(form);
2477 	  Window_To_Buffer(form, field);
2478 	  result = E_REQUEST_DENIED;
2479 	}
2480     }
2481   else
2482     result = E_OK;		/* wrapping was not necessary */
2483   return (result);
2484 }
2485 
2486 /*----------------------------------------------------------------------------
2487   Field Editing routines
2488   --------------------------------------------------------------------------*/
2489 
2490 /*---------------------------------------------------------------------------
2491 |   Facility      :  libnform
2492 |   Function      :  static int Field_Editing(
2493 |                                    int (* const fct) (FORM *),
2494 |                                    FORM * form)
2495 |
2496 |   Description   :  Generic routine for field editing requests. The driver
2497 |                    routines are only called for editable fields, the
2498 |                    _WINDOW_MODIFIED flag is set if editing occurred.
2499 |                    This is somewhat special due to the overload semantics
2500 |                    of the NEW_LINE and DEL_PREV requests.
2501 |
2502 |   Return Values :  Error code from low level drivers.
2503 +--------------------------------------------------------------------------*/
2504 static int
2505 Field_Editing(int (*const fct) (FORM *), FORM *form)
2506 {
2507   int res = E_REQUEST_DENIED;
2508 
2509   /* We have to deal here with the specific case of the overloaded
2510      behavior of New_Line and Delete_Previous requests.
2511      They may end up in navigational requests if we are on the first
2512      character in a field. But navigation is also allowed on non-
2513      editable fields.
2514    */
2515   if ((fct == FE_Delete_Previous) &&
2516       ((unsigned)form->opts & O_BS_OVERLOAD) &&
2517       First_Position_In_Current_Field(form))
2518     {
2519       res = Inter_Field_Navigation(FN_Previous_Field, form);
2520     }
2521   else
2522     {
2523       if (fct == FE_New_Line)
2524 	{
2525 	  if (((unsigned)form->opts & O_NL_OVERLOAD) &&
2526 	      First_Position_In_Current_Field(form))
2527 	    {
2528 	      res = Inter_Field_Navigation(FN_Next_Field, form);
2529 	    }
2530 	  else
2531 	    /* FE_New_Line deals itself with the _WINDOW_MODIFIED flag */
2532 	    res = fct(form);
2533 	}
2534       else
2535 	{
2536 	  /* From now on, everything must be editable */
2537 	  if ((unsigned)form->current->opts & O_EDIT)
2538 	    {
2539 	      res = fct(form);
2540 	      if (res == E_OK)
2541 		SetStatus(form, _WINDOW_MODIFIED);
2542 	    }
2543 	}
2544     }
2545   return res;
2546 }
2547 
2548 /*---------------------------------------------------------------------------
2549 |   Facility      :  libnform
2550 |   Function      :  static int FE_New_Line(FORM * form)
2551 |
2552 |   Description   :  Perform a new line request. This is rather complex
2553 |                    compared to other routines in this code due to the
2554 |                    rather difficult to understand description in the
2555 |                    manuals.
2556 |
2557 |   Return Values :  E_OK               - success
2558 |                    E_REQUEST_DENIED   - new line not allowed
2559 |                    E_SYSTEM_ERROR     - system error
2560 +--------------------------------------------------------------------------*/
2561 static int
2562 FE_New_Line(FORM *form)
2563 {
2564   FIELD *field = form->current;
2565   FIELD_CELL *bp, *t;
2566   bool Last_Row = ((field->drows - 1) == form->currow);
2567 
2568   T((T_CALLED("FE_New_Line(%p)"), (void *)form));
2569   if (form->status & _OVLMODE)
2570     {
2571       if (Last_Row &&
2572 	  (!(Growable(field) && !Single_Line_Field(field))))
2573 	{
2574 	  if (!((unsigned)form->opts & O_NL_OVERLOAD))
2575 	    returnCode(E_REQUEST_DENIED);
2576 	  wmove(form->w, form->currow, form->curcol);
2577 	  wclrtoeol(form->w);
2578 	  /* we have to set this here, although it is also
2579 	     handled in the generic routine. The reason is,
2580 	     that FN_Next_Field may fail, but the form is
2581 	     definitively changed */
2582 	  SetStatus(form, _WINDOW_MODIFIED);
2583 	  returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2584 	}
2585       else
2586 	{
2587 	  if (Last_Row && !Field_Grown(field, 1))
2588 	    {
2589 	      /* N.B.: due to the logic in the 'if', LastRow==TRUE
2590 	         means here that the field is growable and not
2591 	         a single-line field */
2592 	      returnCode(E_SYSTEM_ERROR);
2593 	    }
2594 	  wmove(form->w, form->currow, form->curcol);
2595 	  wclrtoeol(form->w);
2596 	  form->currow++;
2597 	  form->curcol = 0;
2598 	  SetStatus(form, _WINDOW_MODIFIED);
2599 	  returnCode(E_OK);
2600 	}
2601     }
2602   else
2603     {
2604       /* Insert Mode */
2605       if (Last_Row &&
2606 	  !(Growable(field) && !Single_Line_Field(field)))
2607 	{
2608 	  if (!((unsigned)form->opts & O_NL_OVERLOAD))
2609 	    returnCode(E_REQUEST_DENIED);
2610 	  returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2611 	}
2612       else
2613 	{
2614 	  bool May_Do_It = !Last_Row && Is_There_Room_For_A_Line(form);
2615 
2616 	  if (!(May_Do_It || Growable(field)))
2617 	    returnCode(E_REQUEST_DENIED);
2618 	  if (!May_Do_It && !Field_Grown(field, 1))
2619 	    returnCode(E_SYSTEM_ERROR);
2620 
2621 	  bp = Address_Of_Current_Position_In_Buffer(form);
2622 	  t = After_End_Of_Data(bp, field->dcols - form->curcol);
2623 	  wmove(form->w, form->currow, form->curcol);
2624 	  wclrtoeol(form->w);
2625 	  form->currow++;
2626 	  form->curcol = 0;
2627 	  wmove(form->w, form->currow, form->curcol);
2628 	  winsertln(form->w);
2629 	  myADDNSTR(form->w, bp, (int)(t - bp));
2630 	  SetStatus(form, _WINDOW_MODIFIED);
2631 	  returnCode(E_OK);
2632 	}
2633     }
2634 }
2635 
2636 /*---------------------------------------------------------------------------
2637 |   Facility      :  libnform
2638 |   Function      :  static int FE_Insert_Character(FORM * form)
2639 |
2640 |   Description   :  Insert blank character at the cursor position
2641 |
2642 |   Return Values :  E_OK
2643 |                    E_REQUEST_DENIED
2644 +--------------------------------------------------------------------------*/
2645 static int
2646 FE_Insert_Character(FORM *form)
2647 {
2648   FIELD *field = form->current;
2649   int result = E_REQUEST_DENIED;
2650 
2651   T((T_CALLED("FE_Insert_Character(%p)"), (void *)form));
2652   if (Check_Char(form, field, field->type, (int)C_BLANK,
2653 		 (TypeArgument *)(field->arg)))
2654     {
2655       bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
2656 
2657       if (There_Is_Room ||
2658 	  ((Single_Line_Field(field) && Growable(field))))
2659 	{
2660 	  if (!There_Is_Room && !Field_Grown(field, 1))
2661 	    result = E_SYSTEM_ERROR;
2662 	  else
2663 	    {
2664 	      winsch(form->w, (chtype)C_BLANK);
2665 	      result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form);
2666 	    }
2667 	}
2668     }
2669   returnCode(result);
2670 }
2671 
2672 /*---------------------------------------------------------------------------
2673 |   Facility      :  libnform
2674 |   Function      :  static int FE_Insert_Line(FORM * form)
2675 |
2676 |   Description   :  Insert a blank line at the cursor position
2677 |
2678 |   Return Values :  E_OK               - success
2679 |                    E_REQUEST_DENIED   - line can not be inserted
2680 +--------------------------------------------------------------------------*/
2681 static int
2682 FE_Insert_Line(FORM *form)
2683 {
2684   FIELD *field = form->current;
2685   int result = E_REQUEST_DENIED;
2686 
2687   T((T_CALLED("FE_Insert_Line(%p)"), (void *)form));
2688   if (Check_Char(form, field,
2689 		 field->type, (int)C_BLANK, (TypeArgument *)(field->arg)))
2690     {
2691       bool Maybe_Done = (form->currow != (field->drows - 1)) &&
2692       Is_There_Room_For_A_Line(form);
2693 
2694       if (!Single_Line_Field(field) &&
2695 	  (Maybe_Done || Growable(field)))
2696 	{
2697 	  if (!Maybe_Done && !Field_Grown(field, 1))
2698 	    result = E_SYSTEM_ERROR;
2699 	  else
2700 	    {
2701 	      form->curcol = 0;
2702 	      winsertln(form->w);
2703 	      result = E_OK;
2704 	    }
2705 	}
2706     }
2707   returnCode(result);
2708 }
2709 
2710 /*---------------------------------------------------------------------------
2711 |   Facility      :  libnform
2712 |   Function      :  static int FE_Delete_Character(FORM * form)
2713 |
2714 |   Description   :  Delete character at the cursor position
2715 |
2716 |   Return Values :  E_OK    - success
2717 +--------------------------------------------------------------------------*/
2718 static int
2719 FE_Delete_Character(FORM *form)
2720 {
2721   T((T_CALLED("FE_Delete_Character(%p)"), (void *)form));
2722   DeleteChar(form);
2723   returnCode(E_OK);
2724 }
2725 
2726 /*---------------------------------------------------------------------------
2727 |   Facility      :  libnform
2728 |   Function      :  static int FE_Delete_Previous(FORM * form)
2729 |
2730 |   Description   :  Delete character before cursor. Again this is a rather
2731 |                    difficult piece compared to others due to the overloading
2732 |                    semantics of backspace.
2733 |                    N.B.: The case of overloaded BS on first field position
2734 |                          is already handled in the generic routine.
2735 |
2736 |   Return Values :  E_OK                - success
2737 |                    E_REQUEST_DENIED    - Character can't be deleted
2738 +--------------------------------------------------------------------------*/
2739 static int
2740 FE_Delete_Previous(FORM *form)
2741 {
2742   FIELD *field = form->current;
2743 
2744   T((T_CALLED("FE_Delete_Previous(%p)"), (void *)form));
2745   if (First_Position_In_Current_Field(form))
2746     returnCode(E_REQUEST_DENIED);
2747 
2748   if ((--(form->curcol)) < 0)
2749     {
2750       FIELD_CELL *this_line, *prev_line, *prev_end, *this_end;
2751       int this_row = form->currow;
2752 
2753       form->curcol++;
2754       if (form->status & _OVLMODE)
2755 	returnCode(E_REQUEST_DENIED);
2756 
2757       prev_line = Address_Of_Row_In_Buffer(field, (form->currow - 1));
2758       this_line = Address_Of_Row_In_Buffer(field, (form->currow));
2759       Synchronize_Buffer(form);
2760       prev_end = After_End_Of_Data(prev_line, field->dcols);
2761       this_end = After_End_Of_Data(this_line, field->dcols);
2762       if ((int)(this_end - this_line) >
2763 	  (field->cols - (int)(prev_end - prev_line)))
2764 	returnCode(E_REQUEST_DENIED);
2765       wmove(form->w, form->currow, form->curcol);
2766       wdeleteln(form->w);
2767       Adjust_Cursor_Position(form, prev_end);
2768       /*
2769        * If we did not really move to the previous line, help the user a
2770        * little.  It is however a little inconsistent.  Normally, when
2771        * backspacing around the point where text wraps to a new line in a
2772        * multi-line form, we absorb one keystroke for the wrapping point.  That
2773        * is consistent with SVr4 forms.  However, SVr4 does not allow typing
2774        * into the last column of the field, and requires the user to enter a
2775        * newline to move to the next line.  Therefore it can consistently eat
2776        * that keystroke.  Since ncurses allows the last column, it wraps
2777        * automatically (given the proper options).  But we cannot eat the
2778        * keystroke to back over the wrapping point, since that would put the
2779        * cursor past the end of the form field.  In this case, just delete the
2780        * character at the end of the field.
2781        */
2782       if (form->currow == this_row && this_row > 0)
2783 	{
2784 	  form->currow -= 1;
2785 	  form->curcol = field->dcols - 1;
2786 	  DeleteChar(form);
2787 	}
2788       else
2789 	{
2790 	  wmove(form->w, form->currow, form->curcol);
2791 	  myADDNSTR(form->w, this_line, (int)(this_end - this_line));
2792 	}
2793     }
2794   else
2795     {
2796       DeleteChar(form);
2797     }
2798   returnCode(E_OK);
2799 }
2800 
2801 /*---------------------------------------------------------------------------
2802 |   Facility      :  libnform
2803 |   Function      :  static int FE_Delete_Line(FORM * form)
2804 |
2805 |   Description   :  Delete line at cursor position.
2806 |
2807 |   Return Values :  E_OK  - success
2808 +--------------------------------------------------------------------------*/
2809 static int
2810 FE_Delete_Line(FORM *form)
2811 {
2812   T((T_CALLED("FE_Delete_Line(%p)"), (void *)form));
2813   form->curcol = 0;
2814   wdeleteln(form->w);
2815   returnCode(E_OK);
2816 }
2817 
2818 /*---------------------------------------------------------------------------
2819 |   Facility      :  libnform
2820 |   Function      :  static int FE_Delete_Word(FORM * form)
2821 |
2822 |   Description   :  Delete word at cursor position
2823 |
2824 |   Return Values :  E_OK               - success
2825 |                    E_REQUEST_DENIED   - failure
2826 +--------------------------------------------------------------------------*/
2827 static int
2828 FE_Delete_Word(FORM *form)
2829 {
2830   FIELD *field = form->current;
2831   FIELD_CELL *bp = Address_Of_Current_Row_In_Buffer(form);
2832   FIELD_CELL *ep = bp + field->dcols;
2833   FIELD_CELL *cp = bp + form->curcol;
2834   FIELD_CELL *s;
2835 
2836   T((T_CALLED("FE_Delete_Word(%p)"), (void *)form));
2837   Synchronize_Buffer(form);
2838   if (ISBLANK(*cp))
2839     returnCode(E_REQUEST_DENIED);	/* not in word */
2840 
2841   /* move cursor to begin of word and erase to end of screen-line */
2842   Adjust_Cursor_Position(form,
2843 			 After_Last_Whitespace_Character(bp, form->curcol));
2844   wmove(form->w, form->currow, form->curcol);
2845   wclrtoeol(form->w);
2846 
2847   /* skip over word in buffer */
2848   s = Get_First_Whitespace_Character(cp, (int)(ep - cp));
2849   /* to begin of next word    */
2850   s = Get_Start_Of_Data(s, (int)(ep - s));
2851   if ((s != cp) && !ISBLANK(*s))
2852     {
2853       /* copy remaining line to window */
2854       myADDNSTR(form->w, s, (int)(s - After_End_Of_Data(s, (int)(ep - s))));
2855     }
2856   returnCode(E_OK);
2857 }
2858 
2859 /*---------------------------------------------------------------------------
2860 |   Facility      :  libnform
2861 |   Function      :  static int FE_Clear_To_End_Of_Line(FORM * form)
2862 |
2863 |   Description   :  Clear to end of current line.
2864 |
2865 |   Return Values :  E_OK   - success
2866 +--------------------------------------------------------------------------*/
2867 static int
2868 FE_Clear_To_End_Of_Line(FORM *form)
2869 {
2870   T((T_CALLED("FE_Clear_To_End_Of_Line(%p)"), (void *)form));
2871   wmove(form->w, form->currow, form->curcol);
2872   wclrtoeol(form->w);
2873   returnCode(E_OK);
2874 }
2875 
2876 /*---------------------------------------------------------------------------
2877 |   Facility      :  libnform
2878 |   Function      :  static int FE_Clear_To_End_Of_Field(FORM * form)
2879 |
2880 |   Description   :  Clear to end of field.
2881 |
2882 |   Return Values :  E_OK   - success
2883 +--------------------------------------------------------------------------*/
2884 static int
2885 FE_Clear_To_End_Of_Field(FORM *form)
2886 {
2887   T((T_CALLED("FE_Clear_To_End_Of_Field(%p)"), (void *)form));
2888   wmove(form->w, form->currow, form->curcol);
2889   wclrtobot(form->w);
2890   returnCode(E_OK);
2891 }
2892 
2893 /*---------------------------------------------------------------------------
2894 |   Facility      :  libnform
2895 |   Function      :  static int FE_Clear_Field(FORM * form)
2896 |
2897 |   Description   :  Clear entire field.
2898 |
2899 |   Return Values :  E_OK   - success
2900 +--------------------------------------------------------------------------*/
2901 static int
2902 FE_Clear_Field(FORM *form)
2903 {
2904   T((T_CALLED("FE_Clear_Field(%p)"), (void *)form));
2905   form->currow = form->curcol = 0;
2906   werase(form->w);
2907   returnCode(E_OK);
2908 }
2909 /*----------------------------------------------------------------------------
2910   END of Field Editing routines
2911   --------------------------------------------------------------------------*/
2912 
2913 /*----------------------------------------------------------------------------
2914   Edit Mode routines
2915   --------------------------------------------------------------------------*/
2916 
2917 /*---------------------------------------------------------------------------
2918 |   Facility      :  libnform
2919 |   Function      :  static int EM_Overlay_Mode(FORM * form)
2920 |
2921 |   Description   :  Switch to overlay mode.
2922 |
2923 |   Return Values :  E_OK   - success
2924 +--------------------------------------------------------------------------*/
2925 static int
2926 EM_Overlay_Mode(FORM *form)
2927 {
2928   T((T_CALLED("EM_Overlay_Mode(%p)"), (void *)form));
2929   SetStatus(form, _OVLMODE);
2930   returnCode(E_OK);
2931 }
2932 
2933 /*---------------------------------------------------------------------------
2934 |   Facility      :  libnform
2935 |   Function      :  static int EM_Insert_Mode(FORM * form)
2936 |
2937 |   Description   :  Switch to insert mode
2938 |
2939 |   Return Values :  E_OK   - success
2940 +--------------------------------------------------------------------------*/
2941 static int
2942 EM_Insert_Mode(FORM *form)
2943 {
2944   T((T_CALLED("EM_Insert_Mode(%p)"), (void *)form));
2945   ClrStatus(form, _OVLMODE);
2946   returnCode(E_OK);
2947 }
2948 
2949 /*----------------------------------------------------------------------------
2950   END of Edit Mode routines
2951   --------------------------------------------------------------------------*/
2952 
2953 /*----------------------------------------------------------------------------
2954   Helper routines for Choice Requests
2955   --------------------------------------------------------------------------*/
2956 
2957 /*---------------------------------------------------------------------------
2958 |   Facility      :  libnform
2959 |   Function      :  static bool Next_Choice(FORM * form,
2960 |                                            FIELDTYPE * typ,
2961 |                                            FIELD * field,
2962 |                                            TypeArgument *argp)
2963 |
2964 |   Description   :  Get the next field choice. For linked types this is
2965 |                    done recursively.
2966 |
2967 |   Return Values :  TRUE    - next choice successfully retrieved
2968 |                    FALSE   - couldn't retrieve next choice
2969 +--------------------------------------------------------------------------*/
2970 static bool
2971 Next_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
2972 {
2973   if (!typ || !(typ->status & _HAS_CHOICE))
2974     return FALSE;
2975 
2976   if (typ->status & _LINKED_TYPE)
2977     {
2978       assert(argp);
2979       return (
2980 	       Next_Choice(form, typ->left, field, argp->left) ||
2981 	       Next_Choice(form, typ->right, field, argp->right));
2982     }
2983   else
2984     {
2985 #if NCURSES_INTEROP_FUNCS
2986       assert(typ->enum_next.onext);
2987       if (typ->status & _GENERIC)
2988 	return typ->enum_next.gnext(form, field, (void *)argp);
2989       else
2990 	return typ->enum_next.onext(field, (void *)argp);
2991 #else
2992       assert(typ->next);
2993       return typ->next(field, (void *)argp);
2994 #endif
2995     }
2996 }
2997 
2998 /*---------------------------------------------------------------------------
2999 |   Facility      :  libnform
3000 |   Function      :  static bool Previous_Choice(FORM * form,
3001 |                                                FIELDTYPE * typ,
3002 |                                                FIELD * field,
3003 |                                                TypeArgument *argp)
3004 |
3005 |   Description   :  Get the previous field choice. For linked types this
3006 |                    is done recursively.
3007 |
3008 |   Return Values :  TRUE    - previous choice successfully retrieved
3009 |                    FALSE   - couldn't retrieve previous choice
3010 +--------------------------------------------------------------------------*/
3011 static bool
3012 Previous_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3013 {
3014   if (!typ || !(typ->status & _HAS_CHOICE))
3015     return FALSE;
3016 
3017   if (typ->status & _LINKED_TYPE)
3018     {
3019       assert(argp);
3020       return (
3021 	       Previous_Choice(form, typ->left, field, argp->left) ||
3022 	       Previous_Choice(form, typ->right, field, argp->right));
3023     }
3024   else
3025     {
3026 #if NCURSES_INTEROP_FUNCS
3027       assert(typ->enum_prev.oprev);
3028       if (typ->status & _GENERIC)
3029 	return typ->enum_prev.gprev(form, field, (void *)argp);
3030       else
3031 	return typ->enum_prev.oprev(field, (void *)argp);
3032 #else
3033       assert(typ->prev);
3034       return typ->prev(field, (void *)argp);
3035 #endif
3036     }
3037 }
3038 /*----------------------------------------------------------------------------
3039   End of Helper routines for Choice Requests
3040   --------------------------------------------------------------------------*/
3041 
3042 /*----------------------------------------------------------------------------
3043   Routines for Choice Requests
3044   --------------------------------------------------------------------------*/
3045 
3046 /*---------------------------------------------------------------------------
3047 |   Facility      :  libnform
3048 |   Function      :  static int CR_Next_Choice(FORM * form)
3049 |
3050 |   Description   :  Get the next field choice.
3051 |
3052 |   Return Values :  E_OK              - success
3053 |                    E_REQUEST_DENIED  - next choice couldn't be retrieved
3054 +--------------------------------------------------------------------------*/
3055 static int
3056 CR_Next_Choice(FORM *form)
3057 {
3058   FIELD *field = form->current;
3059 
3060   T((T_CALLED("CR_Next_Choice(%p)"), (void *)form));
3061   Synchronize_Buffer(form);
3062   returnCode((Next_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3063 	     ? E_OK
3064 	     : E_REQUEST_DENIED);
3065 }
3066 
3067 /*---------------------------------------------------------------------------
3068 |   Facility      :  libnform
3069 |   Function      :  static int CR_Previous_Choice(FORM * form)
3070 |
3071 |   Description   :  Get the previous field choice.
3072 |
3073 |   Return Values :  E_OK              - success
3074 |                    E_REQUEST_DENIED  - prev. choice couldn't be retrieved
3075 +--------------------------------------------------------------------------*/
3076 static int
3077 CR_Previous_Choice(FORM *form)
3078 {
3079   FIELD *field = form->current;
3080 
3081   T((T_CALLED("CR_Previous_Choice(%p)"), (void *)form));
3082   Synchronize_Buffer(form);
3083   returnCode((Previous_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3084 	     ? E_OK
3085 	     : E_REQUEST_DENIED);
3086 }
3087 /*----------------------------------------------------------------------------
3088   End of Routines for Choice Requests
3089   --------------------------------------------------------------------------*/
3090 
3091 /*----------------------------------------------------------------------------
3092   Helper routines for Field Validations.
3093   --------------------------------------------------------------------------*/
3094 
3095 /*---------------------------------------------------------------------------
3096 |   Facility      :  libnform
3097 |   Function      :  static bool Check_Field(FORM* form,
3098 |                                            FIELDTYPE * typ,
3099 |                                            FIELD * field,
3100 |                                            TypeArgument * argp)
3101 |
3102 |   Description   :  Check the field according to its fieldtype and its
3103 |                    actual arguments. For linked fieldtypes this is done
3104 |                    recursively.
3105 |
3106 |   Return Values :  TRUE       - field is valid
3107 |                    FALSE      - field is invalid.
3108 +--------------------------------------------------------------------------*/
3109 static bool
3110 Check_Field(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3111 {
3112   if (typ)
3113     {
3114       if ((unsigned)field->opts & O_NULLOK)
3115 	{
3116 	  FIELD_CELL *bp = field->buf;
3117 
3118 	  assert(bp);
3119 	  while (ISBLANK(*bp))
3120 	    {
3121 	      bp++;
3122 	    }
3123 	  if (CharOf(*bp) == 0)
3124 	    return TRUE;
3125 	}
3126 
3127       if (typ->status & _LINKED_TYPE)
3128 	{
3129 	  assert(argp);
3130 	  return (
3131 		   Check_Field(form, typ->left, field, argp->left) ||
3132 		   Check_Field(form, typ->right, field, argp->right));
3133 	}
3134       else
3135 	{
3136 #if NCURSES_INTEROP_FUNCS
3137 	  if (typ->fieldcheck.ofcheck)
3138 	    {
3139 	      if (typ->status & _GENERIC)
3140 		return typ->fieldcheck.gfcheck(form, field, (void *)argp);
3141 	      else
3142 		return typ->fieldcheck.ofcheck(field, (void *)argp);
3143 	    }
3144 #else
3145 	  if (typ->fcheck)
3146 	    return typ->fcheck(field, (void *)argp);
3147 #endif
3148 	}
3149     }
3150   return TRUE;
3151 }
3152 
3153 /*---------------------------------------------------------------------------
3154 |   Facility      :  libnform
3155 |   Function      :  bool _nc_Internal_Validation(FORM * form )
3156 |
3157 |   Description   :  Validate the current field of the form.
3158 |
3159 |   Return Values :  TRUE  - field is valid
3160 |                    FALSE - field is invalid
3161 +--------------------------------------------------------------------------*/
3162 NCURSES_EXPORT(bool)
3163 _nc_Internal_Validation(FORM *form)
3164 {
3165   FIELD *field;
3166 
3167   field = form->current;
3168 
3169   Synchronize_Buffer(form);
3170   if ((form->status & _FCHECK_REQUIRED) ||
3171       (!((unsigned)field->opts & O_PASSOK)))
3172     {
3173       if (!Check_Field(form, field->type, field, (TypeArgument *)(field->arg)))
3174 	return FALSE;
3175       ClrStatus(form, _FCHECK_REQUIRED);
3176       SetStatus(field, _CHANGED);
3177       Synchronize_Linked_Fields(field);
3178     }
3179   return TRUE;
3180 }
3181 /*----------------------------------------------------------------------------
3182   End of Helper routines for Field Validations.
3183   --------------------------------------------------------------------------*/
3184 
3185 /*----------------------------------------------------------------------------
3186   Routines for Field Validation.
3187   --------------------------------------------------------------------------*/
3188 
3189 /*---------------------------------------------------------------------------
3190 |   Facility      :  libnform
3191 |   Function      :  static int FV_Validation(FORM * form)
3192 |
3193 |   Description   :  Validate the current field of the form.
3194 |
3195 |   Return Values :  E_OK             - field valid
3196 |                    E_INVALID_FIELD  - field not valid
3197 +--------------------------------------------------------------------------*/
3198 static int
3199 FV_Validation(FORM *form)
3200 {
3201   T((T_CALLED("FV_Validation(%p)"), (void *)form));
3202   if (_nc_Internal_Validation(form))
3203     returnCode(E_OK);
3204   else
3205     returnCode(E_INVALID_FIELD);
3206 }
3207 /*----------------------------------------------------------------------------
3208   End of routines for Field Validation.
3209   --------------------------------------------------------------------------*/
3210 
3211 /*----------------------------------------------------------------------------
3212   Helper routines for Inter-Field Navigation
3213   --------------------------------------------------------------------------*/
3214 
3215 /*---------------------------------------------------------------------------
3216 |   Facility      :  libnform
3217 |   Function      :  static FIELD *Next_Field_On_Page(FIELD * field)
3218 |
3219 |   Description   :  Get the next field after the given field on the current
3220 |                    page. The order of fields is the one defined by the
3221 |                    fields array. Only visible and active fields are
3222 |                    counted.
3223 |
3224 |   Return Values :  Pointer to the next field.
3225 +--------------------------------------------------------------------------*/
3226 NCURSES_INLINE static FIELD *
3227 Next_Field_On_Page(FIELD *field)
3228 {
3229   FORM *form = field->form;
3230   FIELD **field_on_page = &form->field[field->index];
3231   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3232   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3233 
3234   do
3235     {
3236       field_on_page =
3237 	(field_on_page == last_on_page) ? first_on_page : field_on_page + 1;
3238       if (Field_Is_Selectable(*field_on_page))
3239 	break;
3240     }
3241   while (field != (*field_on_page));
3242   return (*field_on_page);
3243 }
3244 
3245 /*---------------------------------------------------------------------------
3246 |   Facility      :  libnform
3247 |   Function      :  FIELD* _nc_First_Active_Field(FORM * form)
3248 |
3249 |   Description   :  Get the first active field on the current page,
3250 |                    if there are such. If there are none, get the first
3251 |                    visible field on the page. If there are also none,
3252 |                    we return the first field on page and hope the best.
3253 |
3254 |   Return Values :  Pointer to calculated field.
3255 +--------------------------------------------------------------------------*/
3256 NCURSES_EXPORT(FIELD *)
3257 _nc_First_Active_Field(FORM *form)
3258 {
3259   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3260   FIELD *proposed = Next_Field_On_Page(*last_on_page);
3261 
3262   if (proposed == *last_on_page)
3263     {
3264       /* there might be the special situation, where there is no
3265          active and visible field on the current page. We then select
3266          the first visible field on this readonly page
3267        */
3268       if (Field_Is_Not_Selectable(proposed))
3269 	{
3270 	  FIELD **field = &form->field[proposed->index];
3271 	  FIELD **first = &form->field[form->page[form->curpage].pmin];
3272 
3273 	  do
3274 	    {
3275 	      field = (field == last_on_page) ? first : field + 1;
3276 	      if (((unsigned)(*field)->opts & O_VISIBLE))
3277 		break;
3278 	    }
3279 	  while (proposed != (*field));
3280 
3281 	  proposed = *field;
3282 
3283 	  if ((proposed == *last_on_page) &&
3284 	      !((unsigned)proposed->opts & O_VISIBLE))
3285 	    {
3286 	      /* This means, there is also no visible field on the page.
3287 	         So we propose the first one and hope the very best...
3288 	         Some very clever user has designed a readonly and invisible
3289 	         page on this form.
3290 	       */
3291 	      proposed = *first;
3292 	    }
3293 	}
3294     }
3295   return (proposed);
3296 }
3297 
3298 /*---------------------------------------------------------------------------
3299 |   Facility      :  libnform
3300 |   Function      :  static FIELD *Previous_Field_On_Page(FIELD * field)
3301 |
3302 |   Description   :  Get the previous field before the given field on the
3303 |                    current page. The order of fields is the one defined by
3304 |                    the fields array. Only visible and active fields are
3305 |                    counted.
3306 |
3307 |   Return Values :  Pointer to the previous field.
3308 +--------------------------------------------------------------------------*/
3309 NCURSES_INLINE static FIELD *
3310 Previous_Field_On_Page(FIELD *field)
3311 {
3312   FORM *form = field->form;
3313   FIELD **field_on_page = &form->field[field->index];
3314   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3315   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3316 
3317   do
3318     {
3319       field_on_page =
3320 	(field_on_page == first_on_page) ? last_on_page : field_on_page - 1;
3321       if (Field_Is_Selectable(*field_on_page))
3322 	break;
3323     }
3324   while (field != (*field_on_page));
3325 
3326   return (*field_on_page);
3327 }
3328 
3329 /*---------------------------------------------------------------------------
3330 |   Facility      :  libnform
3331 |   Function      :  static FIELD *Sorted_Next_Field(FIELD * field)
3332 |
3333 |   Description   :  Get the next field after the given field on the current
3334 |                    page. The order of fields is the one defined by the
3335 |                    (row,column) geometry, rows are major.
3336 |
3337 |   Return Values :  Pointer to the next field.
3338 +--------------------------------------------------------------------------*/
3339 NCURSES_INLINE static FIELD *
3340 Sorted_Next_Field(FIELD *field)
3341 {
3342   FIELD *field_on_page = field;
3343 
3344   do
3345     {
3346       field_on_page = field_on_page->snext;
3347       if (Field_Is_Selectable(field_on_page))
3348 	break;
3349     }
3350   while (field_on_page != field);
3351 
3352   return (field_on_page);
3353 }
3354 
3355 /*---------------------------------------------------------------------------
3356 |   Facility      :  libnform
3357 |   Function      :  static FIELD *Sorted_Previous_Field(FIELD * field)
3358 |
3359 |   Description   :  Get the previous field before the given field on the
3360 |                    current page. The order of fields is the one defined
3361 |                    by the (row,column) geometry, rows are major.
3362 |
3363 |   Return Values :  Pointer to the previous field.
3364 +--------------------------------------------------------------------------*/
3365 NCURSES_INLINE static FIELD *
3366 Sorted_Previous_Field(FIELD *field)
3367 {
3368   FIELD *field_on_page = field;
3369 
3370   do
3371     {
3372       field_on_page = field_on_page->sprev;
3373       if (Field_Is_Selectable(field_on_page))
3374 	break;
3375     }
3376   while (field_on_page != field);
3377 
3378   return (field_on_page);
3379 }
3380 
3381 /*---------------------------------------------------------------------------
3382 |   Facility      :  libnform
3383 |   Function      :  static FIELD *Left_Neighbor_Field(FIELD * field)
3384 |
3385 |   Description   :  Get the left neighbor of the field on the same line
3386 |                    and the same page. Cycles through the line.
3387 |
3388 |   Return Values :  Pointer to left neighbor field.
3389 +--------------------------------------------------------------------------*/
3390 NCURSES_INLINE static FIELD *
3391 Left_Neighbor_Field(FIELD *field)
3392 {
3393   FIELD *field_on_page = field;
3394 
3395   /* For a field that has really a left neighbor, the while clause
3396      immediately fails and the loop is left, positioned at the right
3397      neighbor. Otherwise we cycle backwards through the sorted field list
3398      until we enter the same line (from the right end).
3399    */
3400   do
3401     {
3402       field_on_page = Sorted_Previous_Field(field_on_page);
3403     }
3404   while (field_on_page->frow != field->frow);
3405 
3406   return (field_on_page);
3407 }
3408 
3409 /*---------------------------------------------------------------------------
3410 |   Facility      :  libnform
3411 |   Function      :  static FIELD *Right_Neighbor_Field(FIELD * field)
3412 |
3413 |   Description   :  Get the right neighbor of the field on the same line
3414 |                    and the same page.
3415 |
3416 |   Return Values :  Pointer to right neighbor field.
3417 +--------------------------------------------------------------------------*/
3418 NCURSES_INLINE static FIELD *
3419 Right_Neighbor_Field(FIELD *field)
3420 {
3421   FIELD *field_on_page = field;
3422 
3423   /* See the comments on Left_Neighbor_Field to understand how it works */
3424   do
3425     {
3426       field_on_page = Sorted_Next_Field(field_on_page);
3427     }
3428   while (field_on_page->frow != field->frow);
3429 
3430   return (field_on_page);
3431 }
3432 
3433 /*---------------------------------------------------------------------------
3434 |   Facility      :  libnform
3435 |   Function      :  static FIELD *Upper_Neighbor_Field(FIELD * field)
3436 |
3437 |   Description   :  Because of the row-major nature of sorting the fields,
3438 |                    it is more difficult to define whats the upper neighbor
3439 |                    field really means. We define that it must be on a
3440 |                    'previous' line (cyclic order!) and is the rightmost
3441 |                    field laying on the left side of the given field. If
3442 |                    this set is empty, we take the first field on the line.
3443 |
3444 |   Return Values :  Pointer to the upper neighbor field.
3445 +--------------------------------------------------------------------------*/
3446 static FIELD *
3447 Upper_Neighbor_Field(FIELD *field)
3448 {
3449   FIELD *field_on_page = field;
3450   int frow = field->frow;
3451   int fcol = field->fcol;
3452 
3453   /* Walk back to the 'previous' line. The second term in the while clause
3454      just guarantees that we stop if we cycled through the line because
3455      there might be no 'previous' line if the page has just one line.
3456    */
3457   do
3458     {
3459       field_on_page = Sorted_Previous_Field(field_on_page);
3460     }
3461   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3462 
3463   if (field_on_page->frow != frow)
3464     {
3465       /* We really found a 'previous' line. We are positioned at the
3466          rightmost field on this line */
3467       frow = field_on_page->frow;
3468 
3469       /* We walk to the left as long as we are really right of the
3470          field. */
3471       while (field_on_page->frow == frow && field_on_page->fcol > fcol)
3472 	field_on_page = Sorted_Previous_Field(field_on_page);
3473 
3474       /* If we wrapped, just go to the right which is the first field on
3475          the row */
3476       if (field_on_page->frow != frow)
3477 	field_on_page = Sorted_Next_Field(field_on_page);
3478     }
3479 
3480   return (field_on_page);
3481 }
3482 
3483 /*---------------------------------------------------------------------------
3484 |   Facility      :  libnform
3485 |   Function      :  static FIELD *Down_Neighbor_Field(FIELD * field)
3486 |
3487 |   Description   :  Because of the row-major nature of sorting the fields,
3488 |                    its more difficult to define whats the down neighbor
3489 |                    field really means. We define that it must be on a
3490 |                    'next' line (cyclic order!) and is the leftmost
3491 |                    field laying on the right side of the given field. If
3492 |                    this set is empty, we take the last field on the line.
3493 |
3494 |   Return Values :  Pointer to the upper neighbor field.
3495 +--------------------------------------------------------------------------*/
3496 static FIELD *
3497 Down_Neighbor_Field(FIELD *field)
3498 {
3499   FIELD *field_on_page = field;
3500   int frow = field->frow;
3501   int fcol = field->fcol;
3502 
3503   /* Walk forward to the 'next' line. The second term in the while clause
3504      just guarantees that we stop if we cycled through the line because
3505      there might be no 'next' line if the page has just one line.
3506    */
3507   do
3508     {
3509       field_on_page = Sorted_Next_Field(field_on_page);
3510     }
3511   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3512 
3513   if (field_on_page->frow != frow)
3514     {
3515       /* We really found a 'next' line. We are positioned at the rightmost
3516          field on this line */
3517       frow = field_on_page->frow;
3518 
3519       /* We walk to the right as long as we are really left of the
3520          field. */
3521       while (field_on_page->frow == frow && field_on_page->fcol < fcol)
3522 	field_on_page = Sorted_Next_Field(field_on_page);
3523 
3524       /* If we wrapped, just go to the left which is the last field on
3525          the row */
3526       if (field_on_page->frow != frow)
3527 	field_on_page = Sorted_Previous_Field(field_on_page);
3528     }
3529 
3530   return (field_on_page);
3531 }
3532 
3533 /*----------------------------------------------------------------------------
3534   Inter-Field Navigation routines
3535   --------------------------------------------------------------------------*/
3536 
3537 /*---------------------------------------------------------------------------
3538 |   Facility      :  libnform
3539 |   Function      :  static int Inter_Field_Navigation(
3540 |                                           int (* const fct) (FORM *),
3541 |                                           FORM * form)
3542 |
3543 |   Description   :  Generic behavior for changing the current field, the
3544 |                    field is left and a new field is entered. So the field
3545 |                    must be validated and the field init/term hooks must
3546 |                    be called.
3547 |
3548 |   Return Values :  E_OK                - success
3549 |                    E_INVALID_FIELD     - field is invalid
3550 |                    some other          - error from subordinate call
3551 +--------------------------------------------------------------------------*/
3552 static int
3553 Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form)
3554 {
3555   int res;
3556 
3557   if (!_nc_Internal_Validation(form))
3558     res = E_INVALID_FIELD;
3559   else
3560     {
3561       Call_Hook(form, fieldterm);
3562       res = fct(form);
3563       Call_Hook(form, fieldinit);
3564     }
3565   return res;
3566 }
3567 
3568 /*---------------------------------------------------------------------------
3569 |   Facility      :  libnform
3570 |   Function      :  static int FN_Next_Field(FORM * form)
3571 |
3572 |   Description   :  Move to the next field on the current page of the form
3573 |
3574 |   Return Values :  E_OK                 - success
3575 |                    != E_OK              - error from subordinate call
3576 +--------------------------------------------------------------------------*/
3577 static int
3578 FN_Next_Field(FORM *form)
3579 {
3580   T((T_CALLED("FN_Next_Field(%p)"), (void *)form));
3581   returnCode(_nc_Set_Current_Field(form,
3582 				   Next_Field_On_Page(form->current)));
3583 }
3584 
3585 /*---------------------------------------------------------------------------
3586 |   Facility      :  libnform
3587 |   Function      :  static int FN_Previous_Field(FORM * form)
3588 |
3589 |   Description   :  Move to the previous field on the current page of the
3590 |                    form
3591 |
3592 |   Return Values :  E_OK                 - success
3593 |                    != E_OK              - error from subordinate call
3594 +--------------------------------------------------------------------------*/
3595 static int
3596 FN_Previous_Field(FORM *form)
3597 {
3598   T((T_CALLED("FN_Previous_Field(%p)"), (void *)form));
3599   returnCode(_nc_Set_Current_Field(form,
3600 				   Previous_Field_On_Page(form->current)));
3601 }
3602 
3603 /*---------------------------------------------------------------------------
3604 |   Facility      :  libnform
3605 |   Function      :  static int FN_First_Field(FORM * form)
3606 |
3607 |   Description   :  Move to the first field on the current page of the form
3608 |
3609 |   Return Values :  E_OK                 - success
3610 |                    != E_OK              - error from subordinate call
3611 +--------------------------------------------------------------------------*/
3612 static int
3613 FN_First_Field(FORM *form)
3614 {
3615   T((T_CALLED("FN_First_Field(%p)"), (void *)form));
3616   returnCode(_nc_Set_Current_Field(form,
3617 				   Next_Field_On_Page(form->field[form->page[form->curpage].pmax])));
3618 }
3619 
3620 /*---------------------------------------------------------------------------
3621 |   Facility      :  libnform
3622 |   Function      :  static int FN_Last_Field(FORM * form)
3623 |
3624 |   Description   :  Move to the last field on the current page of the form
3625 |
3626 |   Return Values :  E_OK                 - success
3627 |                    != E_OK              - error from subordinate call
3628 +--------------------------------------------------------------------------*/
3629 static int
3630 FN_Last_Field(FORM *form)
3631 {
3632   T((T_CALLED("FN_Last_Field(%p)"), (void *)form));
3633   returnCode(
3634 	      _nc_Set_Current_Field(form,
3635 				    Previous_Field_On_Page(form->field[form->page[form->curpage].pmin])));
3636 }
3637 
3638 /*---------------------------------------------------------------------------
3639 |   Facility      :  libnform
3640 |   Function      :  static int FN_Sorted_Next_Field(FORM * form)
3641 |
3642 |   Description   :  Move to the sorted next field on the current page
3643 |                    of the form.
3644 |
3645 |   Return Values :  E_OK            - success
3646 |                    != E_OK         - error from subordinate call
3647 +--------------------------------------------------------------------------*/
3648 static int
3649 FN_Sorted_Next_Field(FORM *form)
3650 {
3651   T((T_CALLED("FN_Sorted_Next_Field(%p)"), (void *)form));
3652   returnCode(_nc_Set_Current_Field(form,
3653 				   Sorted_Next_Field(form->current)));
3654 }
3655 
3656 /*---------------------------------------------------------------------------
3657 |   Facility      :  libnform
3658 |   Function      :  static int FN_Sorted_Previous_Field(FORM * form)
3659 |
3660 |   Description   :  Move to the sorted previous field on the current page
3661 |                    of the form.
3662 |
3663 |   Return Values :  E_OK            - success
3664 |                    != E_OK         - error from subordinate call
3665 +--------------------------------------------------------------------------*/
3666 static int
3667 FN_Sorted_Previous_Field(FORM *form)
3668 {
3669   T((T_CALLED("FN_Sorted_Previous_Field(%p)"), (void *)form));
3670   returnCode(_nc_Set_Current_Field(form,
3671 				   Sorted_Previous_Field(form->current)));
3672 }
3673 
3674 /*---------------------------------------------------------------------------
3675 |   Facility      :  libnform
3676 |   Function      :  static int FN_Sorted_First_Field(FORM * form)
3677 |
3678 |   Description   :  Move to the sorted first field on the current page
3679 |                    of the form.
3680 |
3681 |   Return Values :  E_OK            - success
3682 |                    != E_OK         - error from subordinate call
3683 +--------------------------------------------------------------------------*/
3684 static int
3685 FN_Sorted_First_Field(FORM *form)
3686 {
3687   T((T_CALLED("FN_Sorted_First_Field(%p)"), (void *)form));
3688   returnCode(_nc_Set_Current_Field(form,
3689 				   Sorted_Next_Field(form->field[form->page[form->curpage].smax])));
3690 }
3691 
3692 /*---------------------------------------------------------------------------
3693 |   Facility      :  libnform
3694 |   Function      :  static int FN_Sorted_Last_Field(FORM * form)
3695 |
3696 |   Description   :  Move to the sorted last field on the current page
3697 |                    of the form.
3698 |
3699 |   Return Values :  E_OK            - success
3700 |                    != E_OK         - error from subordinate call
3701 +--------------------------------------------------------------------------*/
3702 static int
3703 FN_Sorted_Last_Field(FORM *form)
3704 {
3705   T((T_CALLED("FN_Sorted_Last_Field(%p)"), (void *)form));
3706   returnCode(_nc_Set_Current_Field(form,
3707 				   Sorted_Previous_Field(form->field[form->page[form->curpage].smin])));
3708 }
3709 
3710 /*---------------------------------------------------------------------------
3711 |   Facility      :  libnform
3712 |   Function      :  static int FN_Left_Field(FORM * form)
3713 |
3714 |   Description   :  Get the field on the left of the current field on the
3715 |                    same line and the same page. Cycles through the line.
3716 |
3717 |   Return Values :  E_OK            - success
3718 |                    != E_OK         - error from subordinate call
3719 +--------------------------------------------------------------------------*/
3720 static int
3721 FN_Left_Field(FORM *form)
3722 {
3723   T((T_CALLED("FN_Left_Field(%p)"), (void *)form));
3724   returnCode(_nc_Set_Current_Field(form,
3725 				   Left_Neighbor_Field(form->current)));
3726 }
3727 
3728 /*---------------------------------------------------------------------------
3729 |   Facility      :  libnform
3730 |   Function      :  static int FN_Right_Field(FORM * form)
3731 |
3732 |   Description   :  Get the field on the right of the current field on the
3733 |                    same line and the same page. Cycles through the line.
3734 |
3735 |   Return Values :  E_OK            - success
3736 |                    != E_OK         - error from subordinate call
3737 +--------------------------------------------------------------------------*/
3738 static int
3739 FN_Right_Field(FORM *form)
3740 {
3741   T((T_CALLED("FN_Right_Field(%p)"), (void *)form));
3742   returnCode(_nc_Set_Current_Field(form,
3743 				   Right_Neighbor_Field(form->current)));
3744 }
3745 
3746 /*---------------------------------------------------------------------------
3747 |   Facility      :  libnform
3748 |   Function      :  static int FN_Up_Field(FORM * form)
3749 |
3750 |   Description   :  Get the upper neighbor of the current field. This
3751 |                    cycles through the page. See the comments of the
3752 |                    Upper_Neighbor_Field function to understand how
3753 |                    'upper' is defined.
3754 |
3755 |   Return Values :  E_OK            - success
3756 |                    != E_OK         - error from subordinate call
3757 +--------------------------------------------------------------------------*/
3758 static int
3759 FN_Up_Field(FORM *form)
3760 {
3761   T((T_CALLED("FN_Up_Field(%p)"), (void *)form));
3762   returnCode(_nc_Set_Current_Field(form,
3763 				   Upper_Neighbor_Field(form->current)));
3764 }
3765 
3766 /*---------------------------------------------------------------------------
3767 |   Facility      :  libnform
3768 |   Function      :  static int FN_Down_Field(FORM * form)
3769 |
3770 |   Description   :  Get the down neighbor of the current field. This
3771 |                    cycles through the page. See the comments of the
3772 |                    Down_Neighbor_Field function to understand how
3773 |                    'down' is defined.
3774 |
3775 |   Return Values :  E_OK            - success
3776 |                    != E_OK         - error from subordinate call
3777 +--------------------------------------------------------------------------*/
3778 static int
3779 FN_Down_Field(FORM *form)
3780 {
3781   T((T_CALLED("FN_Down_Field(%p)"), (void *)form));
3782   returnCode(_nc_Set_Current_Field(form,
3783 				   Down_Neighbor_Field(form->current)));
3784 }
3785 /*----------------------------------------------------------------------------
3786   END of Field Navigation routines
3787   --------------------------------------------------------------------------*/
3788 
3789 /*----------------------------------------------------------------------------
3790   Helper routines for Page Navigation
3791   --------------------------------------------------------------------------*/
3792 
3793 /*---------------------------------------------------------------------------
3794 |   Facility      :  libnform
3795 |   Function      :  int _nc_Set_Form_Page(FORM * form,
3796 |                                          int page,
3797 |                                          FIELD * field)
3798 |
3799 |   Description   :  Make the given page number the current page and make
3800 |                    the given field the current field on the page. If
3801 |                    for the field NULL is given, make the first field on
3802 |                    the page the current field. The routine acts only
3803 |                    if the requested page is not the current page.
3804 |
3805 |   Return Values :  E_OK                - success
3806 |                    != E_OK             - error from subordinate call
3807 |                    E_BAD_ARGUMENT      - invalid field pointer
3808 |                    E_SYSTEM_ERROR      - some severe basic error
3809 +--------------------------------------------------------------------------*/
3810 NCURSES_EXPORT(int)
3811 _nc_Set_Form_Page(FORM *form, int page, FIELD *field)
3812 {
3813   int res = E_OK;
3814 
3815   if ((form->curpage != page))
3816     {
3817       FIELD *last_field, *field_on_page;
3818 
3819       werase(Get_Form_Window(form));
3820       form->curpage = (short)page;
3821       last_field = field_on_page = form->field[form->page[page].smin];
3822       do
3823 	{
3824 	  if ((unsigned)field_on_page->opts & O_VISIBLE)
3825 	    if ((res = Display_Field(field_on_page)) != E_OK)
3826 	      return (res);
3827 	  field_on_page = field_on_page->snext;
3828 	}
3829       while (field_on_page != last_field);
3830 
3831       if (field)
3832 	res = _nc_Set_Current_Field(form, field);
3833       else
3834 	/* N.B.: we don't encapsulate this by Inter_Field_Navigation(),
3835 	   because this is already executed in a page navigation
3836 	   context that contains field navigation
3837 	 */
3838 	res = FN_First_Field(form);
3839     }
3840   return (res);
3841 }
3842 
3843 /*---------------------------------------------------------------------------
3844 |   Facility      :  libnform
3845 |   Function      :  static int Next_Page_Number(const FORM * form)
3846 |
3847 |   Description   :  Calculate the page number following the current page
3848 |                    number. This cycles if the highest page number is
3849 |                    reached.
3850 |
3851 |   Return Values :  The next page number
3852 +--------------------------------------------------------------------------*/
3853 NCURSES_INLINE static int
3854 Next_Page_Number(const FORM *form)
3855 {
3856   return (form->curpage + 1) % form->maxpage;
3857 }
3858 
3859 /*---------------------------------------------------------------------------
3860 |   Facility      :  libnform
3861 |   Function      :  static int Previous_Page_Number(const FORM * form)
3862 |
3863 |   Description   :  Calculate the page number before the current page
3864 |                    number. This cycles if the first page number is
3865 |                    reached.
3866 |
3867 |   Return Values :  The previous page number
3868 +--------------------------------------------------------------------------*/
3869 NCURSES_INLINE static int
3870 Previous_Page_Number(const FORM *form)
3871 {
3872   return (form->curpage != 0 ? form->curpage - 1 : form->maxpage - 1);
3873 }
3874 
3875 /*----------------------------------------------------------------------------
3876   Page Navigation routines
3877   --------------------------------------------------------------------------*/
3878 
3879 /*---------------------------------------------------------------------------
3880 |   Facility      :  libnform
3881 |   Function      :  static int Page_Navigation(
3882 |                                               int (* const fct) (FORM *),
3883 |                                               FORM * form)
3884 |
3885 |   Description   :  Generic behavior for changing a page. This means
3886 |                    that the field is left and a new field is entered.
3887 |                    So the field must be validated and the field init/term
3888 |                    hooks must be called. Because also the page is changed,
3889 |                    the forms init/term hooks must be called also.
3890 |
3891 |   Return Values :  E_OK                - success
3892 |                    E_INVALID_FIELD     - field is invalid
3893 |                    some other          - error from subordinate call
3894 +--------------------------------------------------------------------------*/
3895 static int
3896 Page_Navigation(int (*const fct) (FORM *), FORM *form)
3897 {
3898   int res;
3899 
3900   if (!_nc_Internal_Validation(form))
3901     res = E_INVALID_FIELD;
3902   else
3903     {
3904       Call_Hook(form, fieldterm);
3905       Call_Hook(form, formterm);
3906       res = fct(form);
3907       Call_Hook(form, forminit);
3908       Call_Hook(form, fieldinit);
3909     }
3910   return res;
3911 }
3912 
3913 /*---------------------------------------------------------------------------
3914 |   Facility      :  libnform
3915 |   Function      :  static int PN_Next_Page(FORM * form)
3916 |
3917 |   Description   :  Move to the next page of the form
3918 |
3919 |   Return Values :  E_OK                - success
3920 |                    != E_OK             - error from subordinate call
3921 +--------------------------------------------------------------------------*/
3922 static int
3923 PN_Next_Page(FORM *form)
3924 {
3925   T((T_CALLED("PN_Next_Page(%p)"), (void *)form));
3926   returnCode(_nc_Set_Form_Page(form, Next_Page_Number(form), (FIELD *)0));
3927 }
3928 
3929 /*---------------------------------------------------------------------------
3930 |   Facility      :  libnform
3931 |   Function      :  static int PN_Previous_Page(FORM * form)
3932 |
3933 |   Description   :  Move to the previous page of the form
3934 |
3935 |   Return Values :  E_OK              - success
3936 |                    != E_OK           - error from subordinate call
3937 +--------------------------------------------------------------------------*/
3938 static int
3939 PN_Previous_Page(FORM *form)
3940 {
3941   T((T_CALLED("PN_Previous_Page(%p)"), (void *)form));
3942   returnCode(_nc_Set_Form_Page(form, Previous_Page_Number(form), (FIELD *)0));
3943 }
3944 
3945 /*---------------------------------------------------------------------------
3946 |   Facility      :  libnform
3947 |   Function      :  static int PN_First_Page(FORM * form)
3948 |
3949 |   Description   :  Move to the first page of the form
3950 |
3951 |   Return Values :  E_OK              - success
3952 |                    != E_OK           - error from subordinate call
3953 +--------------------------------------------------------------------------*/
3954 static int
3955 PN_First_Page(FORM *form)
3956 {
3957   T((T_CALLED("PN_First_Page(%p)"), (void *)form));
3958   returnCode(_nc_Set_Form_Page(form, 0, (FIELD *)0));
3959 }
3960 
3961 /*---------------------------------------------------------------------------
3962 |   Facility      :  libnform
3963 |   Function      :  static int PN_Last_Page(FORM * form)
3964 |
3965 |   Description   :  Move to the last page of the form
3966 |
3967 |   Return Values :  E_OK              - success
3968 |                    != E_OK           - error from subordinate call
3969 +--------------------------------------------------------------------------*/
3970 static int
3971 PN_Last_Page(FORM *form)
3972 {
3973   T((T_CALLED("PN_Last_Page(%p)"), (void *)form));
3974   returnCode(_nc_Set_Form_Page(form, form->maxpage - 1, (FIELD *)0));
3975 }
3976 
3977 /*----------------------------------------------------------------------------
3978   END of Field Navigation routines
3979   --------------------------------------------------------------------------*/
3980 
3981 /*----------------------------------------------------------------------------
3982   Helper routines for the core form driver.
3983   --------------------------------------------------------------------------*/
3984 
3985 # if USE_WIDEC_SUPPORT
3986 /*---------------------------------------------------------------------------
3987 |   Facility      :  libnform
3988 |   Function      :  static int Data_Entry_w(FORM * form, wchar_t c)
3989 |
3990 |   Description   :  Enter the wide character c into at the current
3991 |                    position of the current field of the form.
3992 |
3993 |   Return Values :  E_OK              - success
3994 |                    E_REQUEST_DENIED  - driver could not process the request
3995 |                    E_SYSTEM_ERROR    -
3996 +--------------------------------------------------------------------------*/
3997 static int
3998 Data_Entry_w(FORM *form, wchar_t c)
3999 {
4000   FIELD *field = form->current;
4001   int result = E_REQUEST_DENIED;
4002 
4003   T((T_CALLED("Data_Entry(%p,%s)"), (void *)form, _tracechtype((chtype)c)));
4004   if (((unsigned)field->opts & O_EDIT)
4005 #if FIX_FORM_INACTIVE_BUG
4006       && ((unsigned)field->opts & O_ACTIVE)
4007 #endif
4008     )
4009     {
4010       wchar_t given[2];
4011       cchar_t temp_ch;
4012 
4013       given[0] = c;
4014       given[1] = 1;
4015       setcchar(&temp_ch, given, 0, 0, (void *)0);
4016       if (((unsigned)field->opts & O_BLANK) &&
4017 	  First_Position_In_Current_Field(form) &&
4018 	  !(form->status & _FCHECK_REQUIRED) &&
4019 	  !(form->status & _WINDOW_MODIFIED))
4020 	werase(form->w);
4021 
4022       if (form->status & _OVLMODE)
4023 	{
4024 	  wadd_wch(form->w, &temp_ch);
4025 	}
4026       else
4027 	/* no _OVLMODE */
4028 	{
4029 	  bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
4030 
4031 	  if (!(There_Is_Room ||
4032 		((Single_Line_Field(field) && Growable(field)))))
4033 	    RETURN(E_REQUEST_DENIED);
4034 
4035 	  if (!There_Is_Room && !Field_Grown(field, 1))
4036 	    RETURN(E_SYSTEM_ERROR);
4037 
4038 	  wins_wch(form->w, &temp_ch);
4039 	}
4040 
4041       if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
4042 	{
4043 	  bool End_Of_Field = (((field->drows - 1) == form->currow) &&
4044 			       ((field->dcols - 1) == form->curcol));
4045 
4046 	  form->status |= _WINDOW_MODIFIED;
4047 	  if (End_Of_Field && !Growable(field) && ((unsigned)field->opts & O_AUTOSKIP))
4048 	    result = Inter_Field_Navigation(FN_Next_Field, form);
4049 	  else
4050 	    {
4051 	      if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
4052 		result = E_SYSTEM_ERROR;
4053 	      else
4054 		{
4055 		  /*
4056 		   * We have just added a byte to the form field.  It may have
4057 		   * been part of a multibyte character.  If it was, the
4058 		   * addch_used field is nonzero and we should not try to move
4059 		   * to a new column.
4060 		   */
4061 		  if (WINDOW_EXT(form->w, addch_used) == 0)
4062 		    IFN_Next_Character(form);
4063 
4064 		  result = E_OK;
4065 		}
4066 	    }
4067 	}
4068     }
4069   RETURN(result);
4070 }
4071 # endif
4072 
4073 /*---------------------------------------------------------------------------
4074 |   Facility      :  libnform
4075 |   Function      :  static int Data_Entry(FORM * form,int c)
4076 |
4077 |   Description   :  Enter character c into at the current position of the
4078 |                    current field of the form.
4079 |
4080 |   Return Values :  E_OK              - success
4081 |                    E_REQUEST_DENIED  - driver could not process the request
4082 |                    E_SYSTEM_ERROR    -
4083 +--------------------------------------------------------------------------*/
4084 static int
4085 Data_Entry(FORM *form, int c)
4086 {
4087   FIELD *field = form->current;
4088   int result = E_REQUEST_DENIED;
4089 
4090   T((T_CALLED("Data_Entry(%p,%s)"), (void *)form, _tracechtype((chtype)c)));
4091   if (((unsigned)field->opts & O_EDIT)
4092 #if FIX_FORM_INACTIVE_BUG
4093       && ((unsigned)field->opts & O_ACTIVE)
4094 #endif
4095     )
4096     {
4097       if (((unsigned)field->opts & O_BLANK) &&
4098 	  First_Position_In_Current_Field(form) &&
4099 	  !(form->status & _FCHECK_REQUIRED) &&
4100 	  !(form->status & _WINDOW_MODIFIED))
4101 	werase(form->w);
4102 
4103       if (form->status & _OVLMODE)
4104 	{
4105 	  waddch(form->w, (chtype)c);
4106 	}
4107       else
4108 	/* no _OVLMODE */
4109 	{
4110 	  bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
4111 
4112 	  if (!(There_Is_Room ||
4113 		((Single_Line_Field(field) && Growable(field)))))
4114 	    RETURN(E_REQUEST_DENIED);
4115 
4116 	  if (!There_Is_Room && !Field_Grown(field, 1))
4117 	    RETURN(E_SYSTEM_ERROR);
4118 
4119 	  winsch(form->w, (chtype)c);
4120 	}
4121 
4122       if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
4123 	{
4124 	  bool End_Of_Field = (((field->drows - 1) == form->currow) &&
4125 			       ((field->dcols - 1) == form->curcol));
4126 
4127 	  SetStatus(form, _WINDOW_MODIFIED);
4128 	  if (End_Of_Field && !Growable(field) && ((unsigned)field->opts & O_AUTOSKIP))
4129 	    result = Inter_Field_Navigation(FN_Next_Field, form);
4130 	  else
4131 	    {
4132 	      if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
4133 		result = E_SYSTEM_ERROR;
4134 	      else
4135 		{
4136 #if USE_WIDEC_SUPPORT
4137 		  /*
4138 		   * We have just added a byte to the form field.  It may have
4139 		   * been part of a multibyte character.  If it was, the
4140 		   * addch_used field is nonzero and we should not try to move
4141 		   * to a new column.
4142 		   */
4143 		  if (WINDOW_EXT(form->w, addch_used) == 0)
4144 		    IFN_Next_Character(form);
4145 #else
4146 		  IFN_Next_Character(form);
4147 #endif
4148 		  result = E_OK;
4149 		}
4150 	    }
4151 	}
4152     }
4153   RETURN(result);
4154 }
4155 
4156 /* Structure to describe the binding of a request code to a function.
4157    The member keycode codes the request value as well as the generic
4158    routine to use for the request. The code for the generic routine
4159    is coded in the upper 16 Bits while the request code is coded in
4160    the lower 16 bits.
4161 
4162    In terms of C++ you might think of a request as a class with a
4163    virtual method "perform". The different types of request are
4164    derived from this base class and overload (or not) the base class
4165    implementation of perform.
4166 */
4167 typedef struct
4168 {
4169   int keycode;			/* must be at least 32 bit: hi:mode, lo: key */
4170   int (*cmd) (FORM *);		/* low level driver routine for this key     */
4171 }
4172 Binding_Info;
4173 
4174 /* You may see this is the class-id of the request type class */
4175 #define ID_PN    (0x00000000)	/* Page navigation           */
4176 #define ID_FN    (0x00010000)	/* Inter-Field navigation    */
4177 #define ID_IFN   (0x00020000)	/* Intra-Field navigation    */
4178 #define ID_VSC   (0x00030000)	/* Vertical Scrolling        */
4179 #define ID_HSC   (0x00040000)	/* Horizontal Scrolling      */
4180 #define ID_FE    (0x00050000)	/* Field Editing             */
4181 #define ID_EM    (0x00060000)	/* Edit Mode                 */
4182 #define ID_FV    (0x00070000)	/* Field Validation          */
4183 #define ID_CH    (0x00080000)	/* Choice                    */
4184 #define ID_Mask  (0xffff0000)
4185 #define Key_Mask (0x0000ffff)
4186 #define ID_Shft  (16)
4187 
4188 /* This array holds all the Binding Infos */
4189 /* *INDENT-OFF* */
4190 static const Binding_Info bindings[MAX_FORM_COMMAND - MIN_FORM_COMMAND + 1] =
4191 {
4192   { REQ_NEXT_PAGE    |ID_PN  ,PN_Next_Page},
4193   { REQ_PREV_PAGE    |ID_PN  ,PN_Previous_Page},
4194   { REQ_FIRST_PAGE   |ID_PN  ,PN_First_Page},
4195   { REQ_LAST_PAGE    |ID_PN  ,PN_Last_Page},
4196 
4197   { REQ_NEXT_FIELD   |ID_FN  ,FN_Next_Field},
4198   { REQ_PREV_FIELD   |ID_FN  ,FN_Previous_Field},
4199   { REQ_FIRST_FIELD  |ID_FN  ,FN_First_Field},
4200   { REQ_LAST_FIELD   |ID_FN  ,FN_Last_Field},
4201   { REQ_SNEXT_FIELD  |ID_FN  ,FN_Sorted_Next_Field},
4202   { REQ_SPREV_FIELD  |ID_FN  ,FN_Sorted_Previous_Field},
4203   { REQ_SFIRST_FIELD |ID_FN  ,FN_Sorted_First_Field},
4204   { REQ_SLAST_FIELD  |ID_FN  ,FN_Sorted_Last_Field},
4205   { REQ_LEFT_FIELD   |ID_FN  ,FN_Left_Field},
4206   { REQ_RIGHT_FIELD  |ID_FN  ,FN_Right_Field},
4207   { REQ_UP_FIELD     |ID_FN  ,FN_Up_Field},
4208   { REQ_DOWN_FIELD   |ID_FN  ,FN_Down_Field},
4209 
4210   { REQ_NEXT_CHAR    |ID_IFN ,IFN_Next_Character},
4211   { REQ_PREV_CHAR    |ID_IFN ,IFN_Previous_Character},
4212   { REQ_NEXT_LINE    |ID_IFN ,IFN_Next_Line},
4213   { REQ_PREV_LINE    |ID_IFN ,IFN_Previous_Line},
4214   { REQ_NEXT_WORD    |ID_IFN ,IFN_Next_Word},
4215   { REQ_PREV_WORD    |ID_IFN ,IFN_Previous_Word},
4216   { REQ_BEG_FIELD    |ID_IFN ,IFN_Beginning_Of_Field},
4217   { REQ_END_FIELD    |ID_IFN ,IFN_End_Of_Field},
4218   { REQ_BEG_LINE     |ID_IFN ,IFN_Beginning_Of_Line},
4219   { REQ_END_LINE     |ID_IFN ,IFN_End_Of_Line},
4220   { REQ_LEFT_CHAR    |ID_IFN ,IFN_Left_Character},
4221   { REQ_RIGHT_CHAR   |ID_IFN ,IFN_Right_Character},
4222   { REQ_UP_CHAR      |ID_IFN ,IFN_Up_Character},
4223   { REQ_DOWN_CHAR    |ID_IFN ,IFN_Down_Character},
4224 
4225   { REQ_NEW_LINE     |ID_FE  ,FE_New_Line},
4226   { REQ_INS_CHAR     |ID_FE  ,FE_Insert_Character},
4227   { REQ_INS_LINE     |ID_FE  ,FE_Insert_Line},
4228   { REQ_DEL_CHAR     |ID_FE  ,FE_Delete_Character},
4229   { REQ_DEL_PREV     |ID_FE  ,FE_Delete_Previous},
4230   { REQ_DEL_LINE     |ID_FE  ,FE_Delete_Line},
4231   { REQ_DEL_WORD     |ID_FE  ,FE_Delete_Word},
4232   { REQ_CLR_EOL      |ID_FE  ,FE_Clear_To_End_Of_Line},
4233   { REQ_CLR_EOF      |ID_FE  ,FE_Clear_To_End_Of_Field},
4234   { REQ_CLR_FIELD    |ID_FE  ,FE_Clear_Field},
4235 
4236   { REQ_OVL_MODE     |ID_EM  ,EM_Overlay_Mode},
4237   { REQ_INS_MODE     |ID_EM  ,EM_Insert_Mode},
4238 
4239   { REQ_SCR_FLINE    |ID_VSC ,VSC_Scroll_Line_Forward},
4240   { REQ_SCR_BLINE    |ID_VSC ,VSC_Scroll_Line_Backward},
4241   { REQ_SCR_FPAGE    |ID_VSC ,VSC_Scroll_Page_Forward},
4242   { REQ_SCR_BPAGE    |ID_VSC ,VSC_Scroll_Page_Backward},
4243   { REQ_SCR_FHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Forward},
4244   { REQ_SCR_BHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Backward},
4245 
4246   { REQ_SCR_FCHAR    |ID_HSC ,HSC_Scroll_Char_Forward},
4247   { REQ_SCR_BCHAR    |ID_HSC ,HSC_Scroll_Char_Backward},
4248   { REQ_SCR_HFLINE   |ID_HSC ,HSC_Horizontal_Line_Forward},
4249   { REQ_SCR_HBLINE   |ID_HSC ,HSC_Horizontal_Line_Backward},
4250   { REQ_SCR_HFHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Forward},
4251   { REQ_SCR_HBHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Backward},
4252 
4253   { REQ_VALIDATION   |ID_FV  ,FV_Validation},
4254 
4255   { REQ_NEXT_CHOICE  |ID_CH  ,CR_Next_Choice},
4256   { REQ_PREV_CHOICE  |ID_CH  ,CR_Previous_Choice}
4257 };
4258 /* *INDENT-ON* */
4259 
4260 /*---------------------------------------------------------------------------
4261 |   Facility      :  libnform
4262 |   Function      :  int form_driver(FORM * form,int  c)
4263 |
4264 |   Description   :  This is the workhorse of the forms system. It checks
4265 |                    to determine whether the character c is a request or
4266 |                    data. If it is a request, the form driver executes
4267 |                    the request and returns the result. If it is data
4268 |                    (printable character), it enters the data into the
4269 |                    current position in the current field. If it is not
4270 |                    recognized, the form driver assumes it is an application
4271 |                    defined command and returns E_UNKNOWN_COMMAND.
4272 |                    Application defined command should be defined relative
4273 |                    to MAX_FORM_COMMAND, the maximum value of a request.
4274 |
4275 |   Return Values :  E_OK              - success
4276 |                    E_SYSTEM_ERROR    - system error
4277 |                    E_BAD_ARGUMENT    - an argument is incorrect
4278 |                    E_NOT_POSTED      - form is not posted
4279 |                    E_INVALID_FIELD   - field contents are invalid
4280 |                    E_BAD_STATE       - called from inside a hook routine
4281 |                    E_REQUEST_DENIED  - request failed
4282 |                    E_NOT_CONNECTED   - no fields are connected to the form
4283 |                    E_UNKNOWN_COMMAND - command not known
4284 +--------------------------------------------------------------------------*/
4285 NCURSES_EXPORT(int)
4286 form_driver(FORM *form, int c)
4287 {
4288   const Binding_Info *BI = (Binding_Info *) 0;
4289   int res = E_UNKNOWN_COMMAND;
4290 
4291   T((T_CALLED("form_driver(%p,%d)"), (void *)form, c));
4292 
4293   if (!form)
4294     RETURN(E_BAD_ARGUMENT);
4295 
4296   if (!(form->field))
4297     RETURN(E_NOT_CONNECTED);
4298 
4299   assert(form->page);
4300 
4301   if (c == FIRST_ACTIVE_MAGIC)
4302     {
4303       form->current = _nc_First_Active_Field(form);
4304       RETURN(E_OK);
4305     }
4306 
4307   assert(form->current &&
4308 	 form->current->buf &&
4309 	 (form->current->form == form)
4310     );
4311 
4312   if (form->status & _IN_DRIVER)
4313     RETURN(E_BAD_STATE);
4314 
4315   if (!(form->status & _POSTED))
4316     RETURN(E_NOT_POSTED);
4317 
4318   if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4319       ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4320     {
4321       TR(TRACE_CALLS, ("form_request %s", form_request_name(c)));
4322       BI = &(bindings[c - MIN_FORM_COMMAND]);
4323     }
4324 
4325   if (BI)
4326     {
4327       typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4328       static const Generic_Method Generic_Methods[] =
4329       {
4330 	Page_Navigation,	/* overloaded to call field&form hooks */
4331 	Inter_Field_Navigation,	/* overloaded to call field hooks      */
4332 	NULL,			/* Intra-Field is generic              */
4333 	Vertical_Scrolling,	/* Overloaded to check multi-line      */
4334 	Horizontal_Scrolling,	/* Overloaded to check single-line     */
4335 	Field_Editing,		/* Overloaded to mark modification     */
4336 	NULL,			/* Edit Mode is generic                */
4337 	NULL,			/* Field Validation is generic         */
4338 	NULL			/* Choice Request is generic           */
4339       };
4340       size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4341       size_t method = (size_t) ((BI->keycode >> ID_Shft) & 0xffff);	/* see ID_Mask */
4342 
4343       if ((method >= nMethods) || !(BI->cmd))
4344 	res = E_SYSTEM_ERROR;
4345       else
4346 	{
4347 	  Generic_Method fct = Generic_Methods[method];
4348 
4349 	  if (fct)
4350 	    {
4351 	      res = fct(BI->cmd, form);
4352 	    }
4353 	  else
4354 	    {
4355 	      res = (BI->cmd) (form);
4356 	    }
4357 	}
4358     }
4359 #ifdef NCURSES_MOUSE_VERSION
4360   else if (KEY_MOUSE == c)
4361     {
4362       MEVENT event;
4363       WINDOW *win = form->win ? form->win : StdScreen(Get_Form_Screen(form));
4364       WINDOW *sub = form->sub ? form->sub : win;
4365 
4366       getmouse(&event);
4367       if ((event.bstate & (BUTTON1_CLICKED |
4368 			   BUTTON1_DOUBLE_CLICKED |
4369 			   BUTTON1_TRIPLE_CLICKED))
4370 	  && wenclose(win, event.y, event.x))
4371 	{			/* we react only if the click was in the userwin, that means
4372 				 * inside the form display area or at the decoration window.
4373 				 */
4374 	  int ry = event.y, rx = event.x;	/* screen coordinates */
4375 
4376 	  res = E_REQUEST_DENIED;
4377 	  if (mouse_trafo(&ry, &rx, FALSE))
4378 	    {			/* rx, ry are now "curses" coordinates */
4379 	      if (ry < sub->_begy)
4380 		{		/* we clicked above the display region; this is
4381 				 * interpreted as "scroll up" request
4382 				 */
4383 		  if (event.bstate & BUTTON1_CLICKED)
4384 		    res = form_driver(form, REQ_PREV_FIELD);
4385 		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4386 		    res = form_driver(form, REQ_PREV_PAGE);
4387 		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4388 		    res = form_driver(form, REQ_FIRST_FIELD);
4389 		}
4390 	      else if (ry > sub->_begy + sub->_maxy)
4391 		{		/* we clicked below the display region; this is
4392 				 * interpreted as "scroll down" request
4393 				 */
4394 		  if (event.bstate & BUTTON1_CLICKED)
4395 		    res = form_driver(form, REQ_NEXT_FIELD);
4396 		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4397 		    res = form_driver(form, REQ_NEXT_PAGE);
4398 		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4399 		    res = form_driver(form, REQ_LAST_FIELD);
4400 		}
4401 	      else if (wenclose(sub, event.y, event.x))
4402 		{		/* Inside the area we try to find the hit item */
4403 		  int i;
4404 
4405 		  ry = event.y;
4406 		  rx = event.x;
4407 		  if (wmouse_trafo(sub, &ry, &rx, FALSE))
4408 		    {
4409 		      int min_field = form->page[form->curpage].pmin;
4410 		      int max_field = form->page[form->curpage].pmax;
4411 
4412 		      for (i = min_field; i <= max_field; ++i)
4413 			{
4414 			  FIELD *field = form->field[i];
4415 
4416 			  if (Field_Is_Selectable(field)
4417 			      && Field_encloses(field, ry, rx) == E_OK)
4418 			    {
4419 			      res = _nc_Set_Current_Field(form, field);
4420 			      if (res == E_OK)
4421 				res = _nc_Position_Form_Cursor(form);
4422 			      if (res == E_OK
4423 				  && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4424 				res = E_UNKNOWN_COMMAND;
4425 			      break;
4426 			    }
4427 			}
4428 		    }
4429 		}
4430 	    }
4431 	}
4432       else
4433 	res = E_REQUEST_DENIED;
4434     }
4435 #endif /* NCURSES_MOUSE_VERSION */
4436   else if (!(c & (~(int)MAX_REGULAR_CHARACTER)))
4437     {
4438       /*
4439        * If we're using 8-bit characters, iscntrl+isprint cover the whole set.
4440        * But with multibyte characters, there is a third possibility, i.e.,
4441        * parts of characters that build up into printable characters which are
4442        * not considered printable.
4443        *
4444        * FIXME: the wide-character branch should also use Check_Char().
4445        */
4446 #if USE_WIDEC_SUPPORT
4447       if (!iscntrl(UChar(c)))
4448 #else
4449       if (isprint(UChar(c)) &&
4450 	  Check_Char(form, form->current, form->current->type, c,
4451 		     (TypeArgument *)(form->current->arg)))
4452 #endif
4453 	res = Data_Entry(form, c);
4454     }
4455   _nc_Refresh_Current_Field(form);
4456   RETURN(res);
4457 }
4458 
4459 # if USE_WIDEC_SUPPORT
4460 /*---------------------------------------------------------------------------
4461 |   Facility      :  libnform
4462 |   Function      :  int form_driver_w(FORM * form,int type,wchar_t  c)
4463 |
4464 |   Description   :  This is the workhorse of the forms system.
4465 |
4466 |                    Input is either a key code (request) or a wide char
4467 |                    returned by e.g. get_wch (). The type must be passed
4468 |                    as well,so that we are able to determine whether the char
4469 |                    is a multibyte char or a request.
4470 
4471 |                    If it is a request, the form driver executes
4472 |                    the request and returns the result. If it is data
4473 |                    (printable character), it enters the data into the
4474 |                    current position in the current field. If it is not
4475 |                    recognized, the form driver assumes it is an application
4476 |                    defined command and returns E_UNKNOWN_COMMAND.
4477 |                    Application defined command should be defined relative
4478 |                    to MAX_FORM_COMMAND, the maximum value of a request.
4479 |
4480 |   Return Values :  E_OK              - success
4481 |                    E_SYSTEM_ERROR    - system error
4482 |                    E_BAD_ARGUMENT    - an argument is incorrect
4483 |                    E_NOT_POSTED      - form is not posted
4484 |                    E_INVALID_FIELD   - field contents are invalid
4485 |                    E_BAD_STATE       - called from inside a hook routine
4486 |                    E_REQUEST_DENIED  - request failed
4487 |                    E_NOT_CONNECTED   - no fields are connected to the form
4488 |                    E_UNKNOWN_COMMAND - command not known
4489 +--------------------------------------------------------------------------*/
4490 NCURSES_EXPORT(int)
4491 form_driver_w(FORM *form, int type, wchar_t c)
4492 {
4493   const Binding_Info *BI = (Binding_Info *) 0;
4494   int res = E_UNKNOWN_COMMAND;
4495 
4496   T((T_CALLED("form_driver(%p,%d)"), (void *)form, (int) c));
4497 
4498   if (!form)
4499     RETURN(E_BAD_ARGUMENT);
4500 
4501   if (!(form->field))
4502     RETURN(E_NOT_CONNECTED);
4503 
4504   assert(form->page);
4505 
4506   if (c == (wchar_t)FIRST_ACTIVE_MAGIC)
4507     {
4508       form->current = _nc_First_Active_Field(form);
4509       RETURN(E_OK);
4510     }
4511 
4512   assert(form->current &&
4513 	 form->current->buf &&
4514 	 (form->current->form == form)
4515     );
4516 
4517   if (form->status & _IN_DRIVER)
4518     RETURN(E_BAD_STATE);
4519 
4520   if (!(form->status & _POSTED))
4521     RETURN(E_NOT_POSTED);
4522 
4523   /* check if this is a keycode or a (wide) char */
4524   if (type == KEY_CODE_YES)
4525     {
4526       if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4527 	  ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4528 	BI = &(bindings[c - MIN_FORM_COMMAND]);
4529     }
4530 
4531   if (BI)
4532     {
4533       typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4534       static const Generic_Method Generic_Methods[] =
4535       {
4536 	Page_Navigation,	/* overloaded to call field&form hooks */
4537 	Inter_Field_Navigation,	/* overloaded to call field hooks      */
4538 	NULL,			/* Intra-Field is generic              */
4539 	Vertical_Scrolling,	/* Overloaded to check multi-line      */
4540 	Horizontal_Scrolling,	/* Overloaded to check single-line     */
4541 	Field_Editing,		/* Overloaded to mark modification     */
4542 	NULL,			/* Edit Mode is generic                */
4543 	NULL,			/* Field Validation is generic         */
4544 	NULL			/* Choice Request is generic           */
4545       };
4546       size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4547       size_t method = (size_t) (BI->keycode >> ID_Shft) & 0xffff;	/* see ID_Mask */
4548 
4549       if ((method >= nMethods) || !(BI->cmd))
4550 	res = E_SYSTEM_ERROR;
4551       else
4552 	{
4553 	  Generic_Method fct = Generic_Methods[method];
4554 
4555 	  if (fct)
4556 	    res = fct(BI->cmd, form);
4557 	  else
4558 	    res = (BI->cmd) (form);
4559 	}
4560     }
4561 #ifdef NCURSES_MOUSE_VERSION
4562   else if (KEY_MOUSE == c)
4563     {
4564       MEVENT event;
4565       WINDOW *win = form->win ? form->win : StdScreen(Get_Form_Screen(form));
4566       WINDOW *sub = form->sub ? form->sub : win;
4567 
4568       getmouse(&event);
4569       if ((event.bstate & (BUTTON1_CLICKED |
4570 			   BUTTON1_DOUBLE_CLICKED |
4571 			   BUTTON1_TRIPLE_CLICKED))
4572 	  && wenclose(win, event.y, event.x))
4573 	{			/* we react only if the click was in the userwin, that means
4574 				   * inside the form display area or at the decoration window.
4575 				 */
4576 	  int ry = event.y, rx = event.x;	/* screen coordinates */
4577 
4578 	  res = E_REQUEST_DENIED;
4579 	  if (mouse_trafo(&ry, &rx, FALSE))
4580 	    {			/* rx, ry are now "curses" coordinates */
4581 	      if (ry < sub->_begy)
4582 		{		/* we clicked above the display region; this is
4583 				   * interpreted as "scroll up" request
4584 				 */
4585 		  if (event.bstate & BUTTON1_CLICKED)
4586 		    res = form_driver(form, REQ_PREV_FIELD);
4587 		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4588 		    res = form_driver(form, REQ_PREV_PAGE);
4589 		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4590 		    res = form_driver(form, REQ_FIRST_FIELD);
4591 		}
4592 	      else if (ry > sub->_begy + sub->_maxy)
4593 		{		/* we clicked below the display region; this is
4594 				   * interpreted as "scroll down" request
4595 				 */
4596 		  if (event.bstate & BUTTON1_CLICKED)
4597 		    res = form_driver(form, REQ_NEXT_FIELD);
4598 		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4599 		    res = form_driver(form, REQ_NEXT_PAGE);
4600 		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4601 		    res = form_driver(form, REQ_LAST_FIELD);
4602 		}
4603 	      else if (wenclose(sub, event.y, event.x))
4604 		{		/* Inside the area we try to find the hit item */
4605 		  int i;
4606 
4607 		  ry = event.y;
4608 		  rx = event.x;
4609 		  if (wmouse_trafo(sub, &ry, &rx, FALSE))
4610 		    {
4611 		      int min_field = form->page[form->curpage].pmin;
4612 		      int max_field = form->page[form->curpage].pmax;
4613 
4614 		      for (i = min_field; i <= max_field; ++i)
4615 			{
4616 			  FIELD *field = form->field[i];
4617 
4618 			  if (Field_Is_Selectable(field)
4619 			      && Field_encloses(field, ry, rx) == E_OK)
4620 			    {
4621 			      res = _nc_Set_Current_Field(form, field);
4622 			      if (res == E_OK)
4623 				res = _nc_Position_Form_Cursor(form);
4624 			      if (res == E_OK
4625 				  && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4626 				res = E_UNKNOWN_COMMAND;
4627 			      break;
4628 			    }
4629 			}
4630 		    }
4631 		}
4632 	    }
4633 	}
4634       else
4635 	res = E_REQUEST_DENIED;
4636     }
4637 #endif /* NCURSES_MOUSE_VERSION */
4638   else if (type == OK)
4639     {
4640       res = Data_Entry_w(form, c);
4641     }
4642 
4643   _nc_Refresh_Current_Field(form);
4644   RETURN(res);
4645 }
4646 # endif	/* USE_WIDEC_SUPPORT */
4647 
4648 /*----------------------------------------------------------------------------
4649   Field-Buffer manipulation routines.
4650   The effects of setting a buffer are tightly coupled to the core of the form
4651   driver logic. This is especially true in the case of growable fields.
4652   So I don't separate this into a separate module.
4653   --------------------------------------------------------------------------*/
4654 
4655 /*---------------------------------------------------------------------------
4656 |   Facility      :  libnform
4657 |   Function      :  int set_field_buffer(FIELD *field,
4658 |                                         int buffer, char *value)
4659 |
4660 |   Description   :  Set the given buffer of the field to the given value.
4661 |                    Buffer 0 stores the displayed content of the field.
4662 |                    For dynamic fields this may grow the fieldbuffers if
4663 |                    the length of the value exceeds the current buffer
4664 |                    length. For buffer 0 only printable values are allowed.
4665 |                    For static fields, the value needs not to be zero ter-
4666 |                    minated. It is copied up to the length of the buffer.
4667 |
4668 |   Return Values :  E_OK            - success
4669 |                    E_BAD_ARGUMENT  - invalid argument
4670 |                    E_SYSTEM_ERROR  - system error
4671 +--------------------------------------------------------------------------*/
4672 NCURSES_EXPORT(int)
4673 set_field_buffer(FIELD *field, int buffer, const char *value)
4674 {
4675   FIELD_CELL *p;
4676   int res = E_OK;
4677   int i;
4678   int len;
4679 
4680 #if USE_WIDEC_SUPPORT
4681   FIELD_CELL *widevalue = 0;
4682 #endif
4683 
4684   T((T_CALLED("set_field_buffer(%p,%d,%s)"), (void *)field, buffer, _nc_visbuf(value)));
4685 
4686   if (!field || !value || ((buffer < 0) || (buffer > field->nbuf)))
4687     RETURN(E_BAD_ARGUMENT);
4688 
4689   len = Buffer_Length(field);
4690 
4691   if (Growable(field))
4692     {
4693       /* for a growable field we must assume zero terminated strings, because
4694          somehow we have to detect the length of what should be copied.
4695        */
4696       int vlen = (int)strlen(value);
4697 
4698       if (vlen > len)
4699 	{
4700 	  if (!Field_Grown(field,
4701 			   (int)(1 + (vlen - len) / ((field->rows + field->nrow)
4702 						     * field->cols))))
4703 	    RETURN(E_SYSTEM_ERROR);
4704 
4705 #if !USE_WIDEC_SUPPORT
4706 	  len = vlen;
4707 #endif
4708 	}
4709     }
4710 
4711   p = Address_Of_Nth_Buffer(field, buffer);
4712 
4713 #if USE_WIDEC_SUPPORT
4714   /*
4715    * Use addstr's logic for converting a string to an array of cchar_t's.
4716    * There should be a better way, but this handles nonspacing characters
4717    * and other special cases that we really do not want to handle here.
4718    */
4719 #if NCURSES_EXT_FUNCS
4720   if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
4721 #endif
4722     {
4723       delwin(field->working);
4724       field->working = newpad(1, Buffer_Length(field) + 1);
4725     }
4726   len = Buffer_Length(field);
4727   wclear(field->working);
4728   (void)mvwaddstr(field->working, 0, 0, value);
4729 
4730   if ((widevalue = typeCalloc(FIELD_CELL, len + 1)) == 0)
4731     {
4732       RETURN(E_SYSTEM_ERROR);
4733     }
4734   else
4735     {
4736       for (i = 0; i < field->drows; ++i)
4737 	{
4738 	  (void)mvwin_wchnstr(field->working, 0, (int)i * field->dcols,
4739 			      widevalue + ((int)i * field->dcols),
4740 			      field->dcols);
4741 	}
4742       for (i = 0; i < len; ++i)
4743 	{
4744 	  if (CharEq(myZEROS, widevalue[i]))
4745 	    {
4746 	      while (i < len)
4747 		p[i++] = myBLANK;
4748 	      break;
4749 	    }
4750 	  p[i] = widevalue[i];
4751 	}
4752       free(widevalue);
4753     }
4754 #else
4755   for (i = 0; i < len; ++i)
4756     {
4757       if (value[i] == '\0')
4758 	{
4759 	  while (i < len)
4760 	    p[i++] = myBLANK;
4761 	  break;
4762 	}
4763       p[i] = value[i];
4764     }
4765 #endif
4766 
4767   if (buffer == 0)
4768     {
4769       int syncres;
4770 
4771       if (((syncres = Synchronize_Field(field)) != E_OK) &&
4772 	  (res == E_OK))
4773 	res = syncres;
4774       if (((syncres = Synchronize_Linked_Fields(field)) != E_OK) &&
4775 	  (res == E_OK))
4776 	res = syncres;
4777     }
4778   RETURN(res);
4779 }
4780 
4781 /*---------------------------------------------------------------------------
4782 |   Facility      :  libnform
4783 |   Function      :  char *field_buffer(const FIELD *field,int buffer)
4784 |
4785 |   Description   :  Return the address of the buffer for the field.
4786 |
4787 |   Return Values :  Pointer to buffer or NULL if arguments were invalid.
4788 +--------------------------------------------------------------------------*/
4789 NCURSES_EXPORT(char *)
4790 field_buffer(const FIELD *field, int buffer)
4791 {
4792   char *result = 0;
4793 
4794   T((T_CALLED("field_buffer(%p,%d)"), (const void *)field, buffer));
4795 
4796   if (field && (buffer >= 0) && (buffer <= field->nbuf))
4797     {
4798 #if USE_WIDEC_SUPPORT
4799       FIELD_CELL *data = Address_Of_Nth_Buffer(field, buffer);
4800       size_t need = 0;
4801       int size = Buffer_Length(field);
4802       int n;
4803 
4804       /* determine the number of bytes needed to store the expanded string */
4805       for (n = 0; n < size; ++n)
4806 	{
4807 	  if (!isWidecExt(data[n]) && data[n].chars[0] != L'\0')
4808 	    {
4809 	      mbstate_t state;
4810 	      size_t next;
4811 
4812 	      init_mb(state);
4813 	      next = _nc_wcrtomb(0, data[n].chars[0], &state);
4814 	      if (next > 0)
4815 		need += next;
4816 	    }
4817 	}
4818 
4819       /* allocate a place to store the expanded string */
4820       if (field->expanded[buffer] != 0)
4821 	free(field->expanded[buffer]);
4822       field->expanded[buffer] = typeMalloc(char, need + 1);
4823 
4824       /*
4825        * Expand the multibyte data.
4826        *
4827        * It may also be multi-column data.  In that case, the data for a row
4828        * may be null-padded to align to the dcols/drows layout (or it may
4829        * contain embedded wide-character extensions).  Change the null-padding
4830        * to blanks as needed.
4831        */
4832       if ((result = field->expanded[buffer]) != 0)
4833 	{
4834 	  wclear(field->working);
4835 	  wmove(field->working, 0, 0);
4836 	  for (n = 0; n < size; ++n)
4837 	    {
4838 	      if (!isWidecExt(data[n]) && data[n].chars[0] != L'\0')
4839 		wadd_wch(field->working, &data[n]);
4840 	    }
4841 	  wmove(field->working, 0, 0);
4842 	  winnstr(field->working, result, (int)need);
4843 	}
4844 #else
4845       result = Address_Of_Nth_Buffer(field, buffer);
4846 #endif
4847     }
4848   returnPtr(result);
4849 }
4850 
4851 #if USE_WIDEC_SUPPORT
4852 
4853 /*---------------------------------------------------------------------------
4854 | Convert a multibyte string to a wide-character string.  The result must be
4855 | freed by the caller.
4856 +--------------------------------------------------------------------------*/
4857 NCURSES_EXPORT(wchar_t *)
4858 _nc_Widen_String(char *source, int *lengthp)
4859 {
4860   wchar_t *result = 0;
4861   wchar_t wch;
4862   size_t given = strlen(source);
4863   size_t tries;
4864   int pass;
4865   int status;
4866 
4867 #ifndef state_unused
4868   mbstate_t state;
4869 #endif
4870 
4871   for (pass = 0; pass < 2; ++pass)
4872     {
4873       unsigned need = 0;
4874       size_t passed = 0;
4875 
4876       while (passed < given)
4877 	{
4878 	  bool found = FALSE;
4879 
4880 	  for (tries = 1, status = 0; tries <= (given - passed); ++tries)
4881 	    {
4882 	      int save = source[passed + tries];
4883 
4884 	      source[passed + tries] = 0;
4885 	      reset_mbytes(state);
4886 	      status = check_mbytes(wch, source + passed, tries, state);
4887 	      source[passed + tries] = (char)save;
4888 
4889 	      if (status > 0)
4890 		{
4891 		  found = TRUE;
4892 		  break;
4893 		}
4894 	    }
4895 	  if (found)
4896 	    {
4897 	      if (pass)
4898 		{
4899 		  result[need] = wch;
4900 		}
4901 	      passed += (size_t) status;
4902 	      ++need;
4903 	    }
4904 	  else
4905 	    {
4906 	      if (pass)
4907 		{
4908 		  result[need] = source[passed];
4909 		}
4910 	      ++need;
4911 	      ++passed;
4912 	    }
4913 	}
4914 
4915       if (!pass)
4916 	{
4917 	  if (!need)
4918 	    break;
4919 	  result = typeCalloc(wchar_t, need);
4920 
4921 	  *lengthp = (int)need;
4922 	  if (result == 0)
4923 	    break;
4924 	}
4925     }
4926 
4927   return result;
4928 }
4929 #endif
4930 
4931 /* frm_driver.c ends here */
4932