1/****************************************************************************
2 * Copyright 2018-2019,2020 Thomas E. Dickey                                *
3 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
24 * Except as contained in this notice, the name(s) of the above copyright   *
25 * holders shall not be used in advertising or otherwise to promote the     *
26 * sale, use or other dealings in this Software without prior written       *
27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *   Author:  Juergen Pfeifer, 1995,1997                                    *
32 ****************************************************************************/
33
34#include "form.priv.h"
35
36MODULE_ID("$Id: frm_driver.c,v 1.129 2020/02/02 23:34:34 tom Exp $")
37
38/*----------------------------------------------------------------------------
39  This is the core module of the form library. It contains the majority
40  of the driver routines as well as the form_driver function.
41
42  Essentially this module is nearly the whole library. This is because
43  all the functions in this module depends on some others in the module,
44  so it makes no sense to split them into separate files because they
45  will always be linked together. The only acceptable concern is turnaround
46  time for this module, but now we have all Pentiums or RISCs, so what!
47
48  The driver routines are grouped into nine generic categories:
49
50   a)   Page Navigation            ( all functions prefixed by PN_ )
51        The current page of the form is left and some new page is
52        entered.
53   b)   Inter-Field Navigation     ( all functions prefixed by FN_ )
54        The current field of the form is left and some new field is
55        entered.
56   c)   Intra-Field Navigation     ( all functions prefixed by IFN_ )
57        The current position in the current field is changed.
58   d)   Vertical Scrolling         ( all functions prefixed by VSC_ )
59        Essentially this is a specialization of Intra-Field navigation.
60        It has to check for a multi-line field.
61   e)   Horizontal Scrolling       ( all functions prefixed by HSC_ )
62        Essentially this is a specialization of Intra-Field navigation.
63        It has to check for a single-line field.
64   f)   Field Editing              ( all functions prefixed by FE_ )
65        The content of the current field is changed
66   g)   Edit Mode requests         ( all functions prefixed by EM_ )
67        Switching between insert and overlay mode
68   h)   Field-Validation requests  ( all functions prefixed by FV_ )
69        Perform verifications of the field.
70   i)   Choice requests            ( all functions prefixed by CR_ )
71        Requests to enumerate possible field values
72  --------------------------------------------------------------------------*/
73
74/*----------------------------------------------------------------------------
75  Some remarks on the placements of assert() macros :
76  I use them only on "strategic" places, i.e. top level entries where
77  I want to make sure that things are set correctly. Throughout subordinate
78  routines I omit them mostly.
79  --------------------------------------------------------------------------*/
80
81/*
82Some options that may effect compatibility in behavior to SVr4 forms,
83but they are here to allow a more intuitive and user friendly behavior of
84our form implementation. This doesn't affect the API, so we feel it is
85uncritical.
86
87The initial implementation tries to stay very close with the behavior
88of the original SVr4 implementation, although in some areas it is quite
89clear that this isn't the most appropriate way. As far as possible this
90sources will allow you to build a forms lib that behaves quite similar
91to SVr4, but now and in the future we will give you better options.
92Perhaps at some time we will make this configurable at runtime.
93*/
94
95/* Implement a more user-friendly previous/next word behavior */
96#define FRIENDLY_PREV_NEXT_WORD (1)
97/* Fix the wrong behavior for forms with all fields inactive */
98#define FIX_FORM_INACTIVE_BUG (1)
99/* Allow dynamic field growth also when navigating past the end */
100#define GROW_IF_NAVIGATE (1)
101
102#if USE_WIDEC_SUPPORT
103#define myADDNSTR(w, s, n) wide_waddnstr(w, s, n)
104#define myINSNSTR(w, s, n) wide_winsnstr(w, s, n)
105#define myINNSTR(w, s, n)  wide_winnstr(w, s, n)
106#define myWCWIDTH(w, y, x) cell_width(w, y, x)
107#else
108#define myADDNSTR(w, s, n) waddnstr(w, s, n)
109#define myINSNSTR(w, s, n) winsnstr(w, s, n)
110#define myINNSTR(w, s, n)  winnstr(w, s, n)
111#define myWCWIDTH(w, y, x) 1
112#endif
113
114/*----------------------------------------------------------------------------
115  Forward references to some internally used static functions
116  --------------------------------------------------------------------------*/
117static int Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form);
118static int FN_Next_Field(FORM *form);
119static int FN_Previous_Field(FORM *form);
120static int FE_New_Line(FORM *);
121static int FE_Delete_Previous(FORM *);
122
123/*----------------------------------------------------------------------------
124  Macro Definitions.
125
126  Some Remarks on that: I use the convention to use UPPERCASE for constants
127  defined by Macros. If I provide a macro as a kind of inline routine to
128  provide some logic, I use my Upper_Lower case style.
129  --------------------------------------------------------------------------*/
130
131/* Calculate the position of a single row in a field buffer */
132#define Position_Of_Row_In_Buffer(field,row) ((row)*(field)->dcols)
133
134/* Calculate start address for the fields buffer# N */
135#define Address_Of_Nth_Buffer(field,N) \
136  ((field)->buf + (N)*(1+Buffer_Length(field)))
137
138/* Calculate the start address of the row in the fields specified buffer# N */
139#define Address_Of_Row_In_Nth_Buffer(field,N,row) \
140  (Address_Of_Nth_Buffer(field,N) + Position_Of_Row_In_Buffer(field,row))
141
142/* Calculate the start address of the row in the fields primary buffer */
143#define Address_Of_Row_In_Buffer(field,row) \
144  Address_Of_Row_In_Nth_Buffer(field,0,row)
145
146/* Calculate the start address of the row in the forms current field
147   buffer# N */
148#define Address_Of_Current_Row_In_Nth_Buffer(form,N) \
149   Address_Of_Row_In_Nth_Buffer((form)->current,N,(form)->currow)
150
151/* Calculate the start address of the row in the forms current field
152   primary buffer */
153#define Address_Of_Current_Row_In_Buffer(form) \
154   Address_Of_Current_Row_In_Nth_Buffer(form,0)
155
156/* Calculate the address of the cursor in the forms current field
157   primary buffer */
158#define Address_Of_Current_Position_In_Nth_Buffer(form,N) \
159   (Address_Of_Current_Row_In_Nth_Buffer(form,N) + (form)->curcol)
160
161/* Calculate the address of the cursor in the forms current field
162   buffer# N */
163#define Address_Of_Current_Position_In_Buffer(form) \
164  Address_Of_Current_Position_In_Nth_Buffer(form,0)
165
166/* Logic to decide whether or not a field is actually a field with
167   vertical or horizontal scrolling */
168#define Is_Scroll_Field(field)          \
169   (((field)->drows > (field)->rows) || \
170    ((field)->dcols > (field)->cols))
171
172/* Logic to decide whether or not a field needs to have an individual window
173   instead of a derived window because it contains invisible parts.
174   This is true for non-public fields and for scrollable fields. */
175#define Has_Invisible_Parts(field)     \
176  (!(Field_Has_Option(field, O_PUBLIC)) || \
177   Is_Scroll_Field(field))
178
179/* Logic to decide whether or not a field needs justification */
180#define Justification_Allowed(field)        \
181   (((field)->just != NO_JUSTIFICATION)  && \
182    (Single_Line_Field(field))           && \
183    ((Field_Has_Option(field, O_STATIC)  && \
184     ((field)->dcols == (field)->cols))  || \
185    Field_Has_Option(field, O_DYNAMIC_JUSTIFY)))
186
187/* Logic to determine whether or not a dynamic field may still grow */
188#define Growable(field) ((field)->status & _MAY_GROW)
189
190/* Macro to set the attributes for a fields window */
191#define Set_Field_Window_Attributes(field,win) \
192(  wbkgdset((win),(chtype)((chtype)((field)->pad) | (field)->back)), \
193   (void) wattrset((win), (int)(field)->fore) )
194
195/* Logic to decide whether or not a field really appears on the form */
196#define Field_Really_Appears(field)         \
197  ((field->form)                          &&\
198   (field->form->status & _POSTED)        &&\
199   (Field_Has_Option(field, O_VISIBLE))   &&\
200   (field->page == field->form->curpage))
201
202/* Logic to determine whether or not we are on the first position in the
203   current field */
204#define First_Position_In_Current_Field(form) \
205  (((form)->currow==0) && ((form)->curcol==0))
206
207#define Minimum(a,b) (((a)<=(b)) ? (a) : (b))
208#define Maximum(a,b) (((a)>=(b)) ? (a) : (b))
209
210/*----------------------------------------------------------------------------
211  Useful constants
212  --------------------------------------------------------------------------*/
213static FIELD_CELL myBLANK = BLANK;
214static FIELD_CELL myZEROS;
215
216#ifdef TRACE
217static void
218check_pos(FORM *form, int lineno)
219{
220  int y, x;
221
222  if (form && form->w)
223    {
224      getyx(form->w, y, x);
225      if (y != form->currow || x != form->curcol)
226	{
227	  T(("CHECKPOS %s@%d have position %d,%d vs want %d,%d",
228	     __FILE__, lineno,
229	     y, x,
230	     form->currow, form->curcol));
231	}
232    }
233}
234#define CHECKPOS(form) check_pos(form, __LINE__)
235#else
236#define CHECKPOS(form)		/* nothing */
237#endif
238
239/*----------------------------------------------------------------------------
240  Wide-character special functions
241  --------------------------------------------------------------------------*/
242#if USE_WIDEC_SUPPORT
243/* add like waddnstr, but using cchar_t* rather than char*
244 */
245static int
246wide_waddnstr(WINDOW *w, const cchar_t *s, int n)
247{
248  int rc = OK;
249
250  while (n-- > 0)
251    {
252      if ((rc = wadd_wch(w, s)) != OK)
253	break;
254      ++s;
255    }
256  return rc;
257}
258
259/* insert like winsnstr, but using cchar_t* rather than char*
260 *
261 * X/Open Curses has no close equivalent; inserts are done only with wchar_t
262 * strings.
263 */
264static int
265wide_winsnstr(WINDOW *w, const cchar_t *s, int n)
266{
267  int code = ERR;
268  int y, x;
269
270  while (n-- > 0)
271    {
272      getyx(w, y, x);
273      if ((code = wins_wch(w, s++)) != OK)
274	break;
275      if ((code = wmove(w, y, x + 1)) != OK)
276	break;
277    }
278  return code;
279}
280
281/* retrieve like winnstr, but using cchar_t*, rather than char*.
282 *
283 * X/Open Curses' closest equivalent, win_wchnstr(), is inconsistent with
284 * winnstr(), since it returns OK rather than the number of items transferred.
285 */
286static int
287wide_winnstr(WINDOW *w, cchar_t *s, int n)
288{
289  int x;
290
291  win_wchnstr(w, s, n);
292  /*
293   * This function is used to extract the text only from the window.
294   * Strip attributes and color from the string so they will not be added
295   * back when copying the string to the window.
296   */
297  for (x = 0; x < n; ++x)
298    {
299      RemAttr(s[x], A_ATTRIBUTES);
300      SetPair(s[x], 0);
301    }
302  return n;
303}
304
305/*
306 * Returns the column of the base of the given cell.
307 */
308static int
309cell_base(WINDOW *win, int y, int x)
310{
311  int result = x;
312
313  while (LEGALYX(win, y, x))
314    {
315      cchar_t *data = &(win->_line[y].text[x]);
316
317      if (isWidecBase(CHDEREF(data)) || !isWidecExt(CHDEREF(data)))
318	{
319	  result = x;
320	  break;
321	}
322      --x;
323    }
324  return result;
325}
326
327/*
328 * Returns the number of columns needed for the given cell in a window.
329 */
330static int
331cell_width(WINDOW *win, int y, int x)
332{
333  int result = 1;
334
335  if (LEGALYX(win, y, x))
336    {
337      cchar_t *data = &(win->_line[y].text[x]);
338
339      if (isWidecExt(CHDEREF(data)))
340	{
341	  /* recur, providing the number of columns to the next character */
342	  result = cell_width(win, y, x - 1);
343	}
344      else
345	{
346	  result = wcwidth(CharOf(CHDEREF(data)));
347	}
348    }
349  return result;
350}
351
352/*
353 * There is no wide-character function such as wdel_wch(), so we must find
354 * all of the cells that comprise a multi-column character and delete them
355 * one-by-one.
356 */
357static void
358delete_char(FORM *form)
359{
360  int cells = cell_width(form->w, form->currow, form->curcol);
361
362  form->curcol = cell_base(form->w, form->currow, form->curcol);
363  wmove(form->w, form->currow, form->curcol);
364  while (cells-- > 0)
365    {
366      wdelch(form->w);
367    }
368}
369#define DeleteChar(form) delete_char(form)
370#else
371#define DeleteChar(form) \
372	  wmove((form)->w, (form)->currow, (form)->curcol), \
373	  wdelch((form)->w)
374#endif
375
376/*---------------------------------------------------------------------------
377|   Facility      :  libnform
378|   Function      :  static char *Get_Start_Of_Data(char * buf, int blen)
379|
380|   Description   :  Return pointer to first non-blank position in buffer.
381|                    If buffer is empty return pointer to buffer itself.
382|
383|   Return Values :  Pointer to first non-blank position in buffer
384+--------------------------------------------------------------------------*/
385NCURSES_INLINE static FIELD_CELL *
386Get_Start_Of_Data(FIELD_CELL *buf, int blen)
387{
388  FIELD_CELL *p = buf;
389  FIELD_CELL *end = &buf[blen];
390
391  assert(buf && blen >= 0);
392  while ((p < end) && ISBLANK(*p))
393    p++;
394  return ((p == end) ? buf : p);
395}
396
397/*---------------------------------------------------------------------------
398|   Facility      :  libnform
399|   Function      :  static char *After_End_Of_Data(char * buf, int blen)
400|
401|   Description   :  Return pointer after last non-blank position in buffer.
402|                    If buffer is empty, return pointer to buffer itself.
403|
404|   Return Values :  Pointer to position after last non-blank position in
405|                    buffer.
406+--------------------------------------------------------------------------*/
407NCURSES_INLINE static FIELD_CELL *
408After_End_Of_Data(FIELD_CELL *buf, int blen)
409{
410  FIELD_CELL *p = &buf[blen];
411
412  assert(buf && blen >= 0);
413  while ((p > buf) && ISBLANK(p[-1]))
414    p--;
415  return (p);
416}
417
418/*---------------------------------------------------------------------------
419|   Facility      :  libnform
420|   Function      :  static char *Get_First_Whitespace_Character(
421|                                     char * buf, int   blen)
422|
423|   Description   :  Position to the first whitespace character.
424|
425|   Return Values :  Pointer to first whitespace character in buffer.
426+--------------------------------------------------------------------------*/
427NCURSES_INLINE static FIELD_CELL *
428Get_First_Whitespace_Character(FIELD_CELL *buf, int blen)
429{
430  FIELD_CELL *p = buf;
431  FIELD_CELL *end = &p[blen];
432
433  assert(buf && blen >= 0);
434  while ((p < end) && !ISBLANK(*p))
435    p++;
436  return ((p == end) ? buf : p);
437}
438
439/*---------------------------------------------------------------------------
440|   Facility      :  libnform
441|   Function      :  static char *After_Last_Whitespace_Character(
442|                                     char * buf, int blen)
443|
444|   Description   :  Get the position after the last whitespace character.
445|
446|   Return Values :  Pointer to position after last whitespace character in
447|                    buffer.
448+--------------------------------------------------------------------------*/
449NCURSES_INLINE static FIELD_CELL *
450After_Last_Whitespace_Character(FIELD_CELL *buf, int blen)
451{
452  FIELD_CELL *p = &buf[blen];
453
454  assert(buf && blen >= 0);
455  while ((p > buf) && !ISBLANK(p[-1]))
456    p--;
457  return (p);
458}
459
460/* Set this to 1 to use the div_t version. This is a good idea if your
461   compiler has an intrinsic div() support. Unfortunately GNU-C has it
462   not yet.
463   N.B.: This only works if form->curcol follows immediately form->currow
464         and both are of type int.
465*/
466#define USE_DIV_T (0)
467
468/*---------------------------------------------------------------------------
469|   Facility      :  libnform
470|   Function      :  static void Adjust_Cursor_Position(
471|                                       FORM * form, const char * pos)
472|
473|   Description   :  Set current row and column of the form to values
474|                    corresponding to the buffer position.
475|
476|   Return Values :  -
477+--------------------------------------------------------------------------*/
478NCURSES_INLINE static void
479Adjust_Cursor_Position(FORM *form, const FIELD_CELL *pos)
480{
481  FIELD *field;
482  int idx;
483
484  field = form->current;
485  assert(pos >= field->buf && field->dcols > 0);
486  idx = (int)(pos - field->buf);
487#if USE_DIV_T
488  *((div_t *) & (form->currow)) = div(idx, field->dcols);
489#else
490  form->currow = idx / field->dcols;
491  form->curcol = idx - field->cols * form->currow;
492#endif
493  if (field->drows < form->currow)
494    form->currow = 0;
495}
496
497/*---------------------------------------------------------------------------
498|   Facility      :  libnform
499|   Function      :  static void Buffer_To_Window(
500|                                      const FIELD  * field,
501|                                      WINDOW * win)
502|
503|   Description   :  Copy the buffer to the window. If it is a multi-line
504|                    field, the buffer is split to the lines of the
505|                    window without any editing.
506|
507|   Return Values :  -
508+--------------------------------------------------------------------------*/
509static void
510Buffer_To_Window(const FIELD *field, WINDOW *win)
511{
512  int width, height;
513  int y, x;
514  int len;
515  int row;
516  FIELD_CELL *pBuffer;
517
518  assert(win && field);
519
520  getyx(win, y, x);
521  width = getmaxx(win);
522  height = getmaxy(win);
523
524  for (row = 0, pBuffer = field->buf;
525       row < height;
526       row++, pBuffer += width)
527    {
528      if ((len = (int)(After_End_Of_Data(pBuffer, width) - pBuffer)) > 0)
529	{
530	  wmove(win, row, 0);
531	  myADDNSTR(win, pBuffer, len);
532	}
533    }
534  wmove(win, y, x);
535}
536
537/*---------------------------------------------------------------------------
538|   Facility      :  libnform
539|   Function      :  void _nc_get_fieldbuffer(
540|                                          WINDOW * win,
541|                                          FIELD  * field,
542|                                          FIELD_CELL * buf)
543|
544|   Description   :  Copy the content of the window into the buffer.
545|                    The multiple lines of a window are simply
546|                    concatenated into the buffer. Pad characters in
547|                    the window will be replaced by blanks in the buffer.
548|
549|   Return Values :  -
550+--------------------------------------------------------------------------*/
551NCURSES_EXPORT(void)
552_nc_get_fieldbuffer(FORM *form, FIELD *field, FIELD_CELL *buf)
553{
554  int pad;
555  int len = 0;
556  FIELD_CELL *p;
557  int row, height;
558  WINDOW *win;
559
560  assert(form && field && buf);
561
562  win = form->w;
563  assert(win);
564
565  pad = field->pad;
566  p = buf;
567  height = getmaxy(win);
568
569  for (row = 0; (row < height) && (row < field->drows); row++)
570    {
571      wmove(win, row, 0);
572      len += myINNSTR(win, p + len, field->dcols);
573    }
574  p[len] = myZEROS;
575
576  /* replace visual padding character by blanks in buffer */
577  if (pad != C_BLANK)
578    {
579      int i;
580
581      for (i = 0; i < len; i++, p++)
582	{
583	  if ((unsigned long)CharOf(*p) == ChCharOf(pad)
584#if USE_WIDEC_SUPPORT
585	      && p->chars[1] == 0
586#endif
587	    )
588	    *p = myBLANK;
589	}
590    }
591}
592
593/*---------------------------------------------------------------------------
594|   Facility      :  libnform
595|   Function      :  static void Window_To_Buffer(
596|                                          FORM   * form,
597|                                          FIELD  * field)
598|
599|   Description   :  Copy the content of the window into the buffer.
600|                    The multiple lines of a window are simply
601|                    concatenated into the buffer. Pad characters in
602|                    the window will be replaced by blanks in the buffer.
603|
604|   Return Values :  -
605+--------------------------------------------------------------------------*/
606static void
607Window_To_Buffer(FORM *form, FIELD *field)
608{
609  _nc_get_fieldbuffer(form, field, field->buf);
610}
611
612/*---------------------------------------------------------------------------
613|   Facility      :  libnform
614|   Function      :  static void Synchronize_Buffer(FORM * form)
615|
616|   Description   :  If there was a change, copy the content of the
617|                    window into the buffer, so the buffer is synchronized
618|                    with the windows content. We have to indicate that the
619|                    buffer needs validation due to the change.
620|
621|   Return Values :  -
622+--------------------------------------------------------------------------*/
623NCURSES_INLINE static void
624Synchronize_Buffer(FORM *form)
625{
626  if (form->status & _WINDOW_MODIFIED)
627    {
628      ClrStatus(form, _WINDOW_MODIFIED);
629      SetStatus(form, _FCHECK_REQUIRED);
630      Window_To_Buffer(form, form->current);
631      wmove(form->w, form->currow, form->curcol);
632    }
633}
634
635/*---------------------------------------------------------------------------
636|   Facility      :  libnform
637|   Function      :  static bool Field_Grown( FIELD *field, int amount)
638|
639|   Description   :  This function is called for growable dynamic fields
640|                    only. It has to increase the buffers and to allocate
641|                    a new window for this field.
642|                    This function has the side effect to set a new
643|                    field-buffer pointer, the dcols and drows values
644|                    as well as a new current Window for the field.
645|
646|   Return Values :  TRUE     - field successfully increased
647|                    FALSE    - there was some error
648+--------------------------------------------------------------------------*/
649static bool
650Field_Grown(FIELD *field, int amount)
651{
652  bool result = FALSE;
653
654  if (field && Growable(field))
655    {
656      bool single_line_field = Single_Line_Field(field);
657      int old_buflen = Buffer_Length(field);
658      int new_buflen;
659      int old_dcols = field->dcols;
660      int old_drows = field->drows;
661      FIELD_CELL *oldbuf = field->buf;
662      FIELD_CELL *newbuf;
663
664      int growth;
665      FORM *form = field->form;
666      bool need_visual_update = ((form != (FORM *)0) &&
667				 (form->status & _POSTED) &&
668				 (form->current == field));
669
670      if (need_visual_update)
671	Synchronize_Buffer(form);
672
673      if (single_line_field)
674	{
675	  growth = field->cols * amount;
676	  if (field->maxgrow)
677	    growth = Minimum(field->maxgrow - field->dcols, growth);
678	  field->dcols += growth;
679	  if (field->dcols == field->maxgrow)
680	    ClrStatus(field, _MAY_GROW);
681	}
682      else
683	{
684	  growth = (field->rows + field->nrow) * amount;
685	  if (field->maxgrow)
686	    growth = Minimum(field->maxgrow - field->drows, growth);
687	  field->drows += growth;
688	  if (field->drows == field->maxgrow)
689	    ClrStatus(field, _MAY_GROW);
690	}
691      /* drows, dcols changed, so we get really the new buffer length */
692      new_buflen = Buffer_Length(field);
693      newbuf = (FIELD_CELL *)malloc(Total_Buffer_Size(field));
694      if (!newbuf)
695	{
696	  /* restore to previous state */
697	  field->dcols = old_dcols;
698	  field->drows = old_drows;
699	  if ((single_line_field && (field->dcols != field->maxgrow)) ||
700	      (!single_line_field && (field->drows != field->maxgrow)))
701	    SetStatus(field, _MAY_GROW);
702	}
703      else
704	{
705	  /* Copy all the buffers.  This is the reason why we can't just use
706	   * realloc().
707	   */
708	  int i, j;
709	  FIELD_CELL *old_bp;
710	  FIELD_CELL *new_bp;
711
712	  result = TRUE;	/* allow sharing of recovery on failure */
713
714	  T((T_CREATE("fieldcell %p"), (void *)newbuf));
715	  field->buf = newbuf;
716	  for (i = 0; i <= field->nbuf; i++)
717	    {
718	      new_bp = Address_Of_Nth_Buffer(field, i);
719	      old_bp = oldbuf + i * (1 + old_buflen);
720	      for (j = 0; j < old_buflen; ++j)
721		new_bp[j] = old_bp[j];
722	      while (j < new_buflen)
723		new_bp[j++] = myBLANK;
724	      new_bp[new_buflen] = myZEROS;
725	    }
726
727#if USE_WIDEC_SUPPORT && NCURSES_EXT_FUNCS
728	  if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
729	    result = FALSE;
730#endif
731
732	  if (need_visual_update && result)
733	    {
734	      WINDOW *new_window = newpad(field->drows, field->dcols);
735
736	      if (new_window != 0)
737		{
738		  assert(form != (FORM *)0);
739		  if (form->w)
740		    delwin(form->w);
741		  form->w = new_window;
742		  Set_Field_Window_Attributes(field, form->w);
743		  werase(form->w);
744		  Buffer_To_Window(field, form->w);
745		  untouchwin(form->w);
746		  wmove(form->w, form->currow, form->curcol);
747		}
748	      else
749		result = FALSE;
750	    }
751
752	  if (result)
753	    {
754	      free(oldbuf);
755	      /* reflect changes in linked fields */
756	      if (field != field->link)
757		{
758		  FIELD *linked_field;
759
760		  for (linked_field = field->link;
761		       linked_field != field;
762		       linked_field = linked_field->link)
763		    {
764		      linked_field->buf = field->buf;
765		      linked_field->drows = field->drows;
766		      linked_field->dcols = field->dcols;
767		    }
768		}
769	    }
770	  else
771	    {
772	      /* restore old state */
773	      field->dcols = old_dcols;
774	      field->drows = old_drows;
775	      field->buf = oldbuf;
776	      if ((single_line_field &&
777		   (field->dcols != field->maxgrow)) ||
778		  (!single_line_field &&
779		   (field->drows != field->maxgrow)))
780		SetStatus(field, _MAY_GROW);
781	      free(newbuf);
782	    }
783	}
784    }
785  return (result);
786}
787
788#ifdef NCURSES_MOUSE_VERSION
789/*---------------------------------------------------------------------------
790|   Facility      :  libnform
791|   Function      :  int Field_encloses(FIELD *field, int ry, int rx)
792|
793|   Description   :  Check if the given coordinates lie within the given field.
794|
795|   Return Values :  E_OK              - success
796|                    E_BAD_ARGUMENT    - invalid form pointer
797|                    E_SYSTEM_ERROR    - form has no current field or
798|                                        field-window
799+--------------------------------------------------------------------------*/
800static int
801Field_encloses(FIELD *field, int ry, int rx)
802{
803  T((T_CALLED("Field_encloses(%p)"), (void *)field));
804  if (field != 0
805      && field->frow <= ry
806      && (field->frow + field->rows) > ry
807      && field->fcol <= rx
808      && (field->fcol + field->cols) > rx)
809    {
810      RETURN(E_OK);
811    }
812  RETURN(E_INVALID_FIELD);
813}
814#endif
815
816/*---------------------------------------------------------------------------
817|   Facility      :  libnform
818|   Function      :  int _nc_Position_Form_Cursor(FORM * form)
819|
820|   Description   :  Position the cursor in the window for the current
821|                    field to be in sync. with the currow and curcol
822|                    values.
823|
824|   Return Values :  E_OK              - success
825|                    E_BAD_ARGUMENT    - invalid form pointer
826|                    E_SYSTEM_ERROR    - form has no current field or
827|                                        field-window
828+--------------------------------------------------------------------------*/
829NCURSES_EXPORT(int)
830_nc_Position_Form_Cursor(FORM *form)
831{
832  FIELD *field;
833  WINDOW *formwin;
834
835  if (!form)
836    return (E_BAD_ARGUMENT);
837
838  if (!form->w || !form->current)
839    return (E_SYSTEM_ERROR);
840
841  field = form->current;
842  formwin = Get_Form_Window(form);
843
844  wmove(form->w, form->currow, form->curcol);
845  if (Has_Invisible_Parts(field))
846    {
847      /* in this case fieldwin isn't derived from formwin, so we have
848         to move the cursor in formwin by hand... */
849      wmove(formwin,
850	    field->frow + form->currow - form->toprow,
851	    field->fcol + form->curcol - form->begincol);
852      wcursyncup(formwin);
853    }
854  else
855    wcursyncup(form->w);
856  return (E_OK);
857}
858
859/*---------------------------------------------------------------------------
860|   Facility      :  libnform
861|   Function      :  int _nc_Refresh_Current_Field(FORM * form)
862|
863|   Description   :  Propagate the changes in the fields window to the
864|                    window of the form.
865|
866|   Return Values :  E_OK              - on success
867|                    E_BAD_ARGUMENT    - invalid form pointer
868|                    E_SYSTEM_ERROR    - general error
869+--------------------------------------------------------------------------*/
870static bool move_after_insert = TRUE;
871NCURSES_EXPORT(int)
872_nc_Refresh_Current_Field(FORM *form)
873{
874  WINDOW *formwin;
875  FIELD *field;
876  bool is_public;
877
878  T((T_CALLED("_nc_Refresh_Current_Field(%p)"), (void *)form));
879
880  if (!form)
881    RETURN(E_BAD_ARGUMENT);
882
883  if (!form->w || !form->current)
884    RETURN(E_SYSTEM_ERROR);
885
886  field = form->current;
887  formwin = Get_Form_Window(form);
888
889  is_public = Field_Has_Option(field, O_PUBLIC);
890
891  if (Is_Scroll_Field(field))
892    {
893      /* Again, in this case the fieldwin isn't derived from formwin,
894         so we have to perform a copy operation. */
895      if (Single_Line_Field(field))
896	{
897	  /* horizontal scrolling */
898	  if (form->curcol < form->begincol)
899	    form->begincol = form->curcol;
900	  else
901	    {
902	      if (form->curcol >= (form->begincol + field->cols))
903		form->begincol = form->curcol - field->cols
904		  + (move_after_insert ? 1 : 0);
905	    }
906	  if (is_public)
907	    copywin(form->w,
908		    formwin,
909		    0,
910		    form->begincol,
911		    field->frow,
912		    field->fcol,
913		    field->frow,
914		    field->cols + field->fcol - 1,
915		    0);
916	}
917      else
918	{
919	  /* A multi-line, i.e. vertical scrolling field */
920	  int row_after_bottom, first_modified_row, first_unmodified_row;
921
922	  if (field->drows > field->rows)
923	    {
924	      row_after_bottom = form->toprow + field->rows;
925	      if (form->currow < form->toprow)
926		{
927		  form->toprow = form->currow;
928		  SetStatus(field, _NEWTOP);
929		}
930	      if (form->currow >= row_after_bottom)
931		{
932		  form->toprow = form->currow - field->rows + 1;
933		  SetStatus(field, _NEWTOP);
934		}
935	      if (field->status & _NEWTOP)
936		{
937		  /* means we have to copy whole range */
938		  first_modified_row = form->toprow;
939		  first_unmodified_row = first_modified_row + field->rows;
940		  ClrStatus(field, _NEWTOP);
941		}
942	      else
943		{
944		  /* we try to optimize : finding the range of touched
945		     lines */
946		  first_modified_row = form->toprow;
947		  while (first_modified_row < row_after_bottom)
948		    {
949		      if (is_linetouched(form->w, first_modified_row))
950			break;
951		      first_modified_row++;
952		    }
953		  first_unmodified_row = first_modified_row;
954		  while (first_unmodified_row < row_after_bottom)
955		    {
956		      if (!is_linetouched(form->w, first_unmodified_row))
957			break;
958		      first_unmodified_row++;
959		    }
960		}
961	    }
962	  else
963	    {
964	      first_modified_row = form->toprow;
965	      first_unmodified_row = first_modified_row + field->rows;
966	    }
967	  if (first_unmodified_row != first_modified_row && is_public)
968	    copywin(form->w,
969		    formwin,
970		    first_modified_row,
971		    0,
972		    field->frow + first_modified_row - form->toprow,
973		    field->fcol,
974		    field->frow + first_unmodified_row - form->toprow - 1,
975		    field->cols + field->fcol - 1,
976		    0);
977	}
978      if (is_public)
979	wsyncup(formwin);
980    }
981  else
982    {
983      /* if the field-window is simply a derived window, i.e. contains no
984       * invisible parts, the whole thing is trivial
985       */
986      if (is_public)
987	wsyncup(form->w);
988    }
989  untouchwin(form->w);
990  returnCode(_nc_Position_Form_Cursor(form));
991}
992
993/*---------------------------------------------------------------------------
994|   Facility      :  libnform
995|   Function      :  static void Perform_Justification(
996|                                        FIELD  * field,
997|                                        WINDOW * win)
998|
999|   Description   :  Output field with requested justification
1000|
1001|   Return Values :  -
1002+--------------------------------------------------------------------------*/
1003static void
1004Perform_Justification(FIELD *field, WINDOW *win)
1005{
1006  FIELD_CELL *bp;
1007  int len;
1008  int col = 0;
1009
1010  bp = (Field_Has_Option(field, O_NO_LEFT_STRIP)
1011	? field->buf
1012	: Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1013  len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
1014
1015  if (len > 0)
1016    {
1017      assert(win && (field->drows == 1));
1018
1019      if (field->cols - len >= 0)
1020	switch (field->just)
1021	  {
1022	  case JUSTIFY_LEFT:
1023	    break;
1024	  case JUSTIFY_CENTER:
1025	    col = (field->cols - len) / 2;
1026	    break;
1027	  case JUSTIFY_RIGHT:
1028	    col = field->cols - len;
1029	    break;
1030	  default:
1031	    break;
1032	  }
1033
1034      wmove(win, 0, col);
1035      myADDNSTR(win, bp, len);
1036    }
1037}
1038
1039/*---------------------------------------------------------------------------
1040|   Facility      :  libnform
1041|   Function      :  static void Undo_Justification(
1042|                                     FIELD  * field,
1043|                                     WINDOW * win)
1044|
1045|   Description   :  Display field without any justification, i.e.
1046|                    left justified
1047|
1048|   Return Values :  -
1049+--------------------------------------------------------------------------*/
1050static void
1051Undo_Justification(FIELD *field, WINDOW *win)
1052{
1053  FIELD_CELL *bp;
1054  int y, x;
1055  int len;
1056
1057  getyx(win, y, x);
1058
1059  bp = (Field_Has_Option(field, O_NO_LEFT_STRIP)
1060	? field->buf
1061	: Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1062  len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
1063
1064  if (len > 0)
1065    {
1066      assert(win);
1067      wmove(win, 0, 0);
1068      myADDNSTR(win, bp, len);
1069    }
1070  wmove(win, y, x);
1071}
1072
1073/*---------------------------------------------------------------------------
1074|   Facility      :  libnform
1075|   Function      :  static bool Check_Char(FORM  *form,
1076|                                           FIELD *field,
1077|                                           FIELDTYPE * typ,
1078|                                           int ch,
1079|                                           TypeArgument *argp)
1080|
1081|   Description   :  Perform a single character check for character ch
1082|                    according to the fieldtype instance.
1083|
1084|   Return Values :  TRUE             - Character is valid
1085|                    FALSE            - Character is invalid
1086+--------------------------------------------------------------------------*/
1087static bool
1088Check_Char(FORM *form,
1089	   FIELD *field,
1090	   FIELDTYPE *typ,
1091	   int ch,
1092	   TypeArgument *argp)
1093{
1094  if (typ)
1095    {
1096      if (typ->status & _LINKED_TYPE)
1097	{
1098	  assert(argp);
1099	  return (
1100		   Check_Char(form, field, typ->left, ch, argp->left) ||
1101		   Check_Char(form, field, typ->right, ch, argp->right));
1102	}
1103      else
1104	{
1105#if NCURSES_INTEROP_FUNCS
1106	  if (typ->charcheck.occheck)
1107	    {
1108	      if (typ->status & _GENERIC)
1109		return typ->charcheck.gccheck(ch, form, field, (void *)argp);
1110	      else
1111		return typ->charcheck.occheck(ch, (void *)argp);
1112	    }
1113#else
1114	  if (typ->ccheck)
1115	    return typ->ccheck(ch, (void *)argp);
1116#endif
1117	}
1118    }
1119  return (!iscntrl(UChar(ch)) ? TRUE : FALSE);
1120}
1121
1122/*---------------------------------------------------------------------------
1123|   Facility      :  libnform
1124|   Function      :  static int Display_Or_Erase_Field(
1125|                                           FIELD * field,
1126|                                           bool bEraseFlag)
1127|
1128|   Description   :  Create a subwindow for the field and display the
1129|                    buffer contents (apply justification if required)
1130|                    or simply erase the field.
1131|
1132|   Return Values :  E_OK           - on success
1133|                    E_SYSTEM_ERROR - some error (typical no memory)
1134+--------------------------------------------------------------------------*/
1135static int
1136Display_Or_Erase_Field(FIELD *field, bool bEraseFlag)
1137{
1138  WINDOW *win;
1139  WINDOW *fwin;
1140
1141  if (!field)
1142    return E_SYSTEM_ERROR;
1143
1144  fwin = Get_Form_Window(field->form);
1145  win = derwin(fwin,
1146	       field->rows, field->cols, field->frow, field->fcol);
1147
1148  if (!win)
1149    return E_SYSTEM_ERROR;
1150  else
1151    {
1152      if (Field_Has_Option(field, O_VISIBLE))
1153	{
1154	  Set_Field_Window_Attributes(field, win);
1155	}
1156      else
1157	{
1158	  (void)wattrset(win, (int)WINDOW_ATTRS(fwin));
1159	}
1160      werase(win);
1161    }
1162
1163  if (!bEraseFlag)
1164    {
1165      if (Field_Has_Option(field, O_PUBLIC))
1166	{
1167	  if (Justification_Allowed(field))
1168	    Perform_Justification(field, win);
1169	  else
1170	    Buffer_To_Window(field, win);
1171	}
1172      ClrStatus(field, _NEWTOP);
1173    }
1174  wsyncup(win);
1175  delwin(win);
1176  return E_OK;
1177}
1178
1179/* Macros to preset the bEraseFlag */
1180#define Display_Field(field) Display_Or_Erase_Field(field,FALSE)
1181#define Erase_Field(field)   Display_Or_Erase_Field(field,TRUE)
1182
1183/*---------------------------------------------------------------------------
1184|   Facility      :  libnform
1185|   Function      :  static int Synchronize_Field(FIELD * field)
1186|
1187|   Description   :  Synchronize the windows content with the value in
1188|                    the buffer.
1189|
1190|   Return Values :  E_OK                - success
1191|                    E_BAD_ARGUMENT      - invalid field pointer
1192|                    E_SYSTEM_ERROR      - some severe basic error
1193+--------------------------------------------------------------------------*/
1194static int
1195Synchronize_Field(FIELD *field)
1196{
1197  FORM *form;
1198  int res = E_OK;
1199
1200  if (!field)
1201    return (E_BAD_ARGUMENT);
1202
1203  if (((form = field->form) != (FORM *)0)
1204      && Field_Really_Appears(field))
1205    {
1206      if (field == form->current)
1207	{
1208	  form->currow = form->curcol = form->toprow = form->begincol = 0;
1209	  werase(form->w);
1210
1211	  if ((Field_Has_Option(field, O_PUBLIC)) && Justification_Allowed(field))
1212	    Undo_Justification(field, form->w);
1213	  else
1214	    Buffer_To_Window(field, form->w);
1215
1216	  SetStatus(field, _NEWTOP);
1217	  res = _nc_Refresh_Current_Field(form);
1218	}
1219      else
1220	res = Display_Field(field);
1221    }
1222  SetStatus(field, _CHANGED);
1223  return (res);
1224}
1225
1226/*---------------------------------------------------------------------------
1227|   Facility      :  libnform
1228|   Function      :  static int Synchronize_Linked_Fields(FIELD * field)
1229|
1230|   Description   :  Propagate the Synchronize_Field function to all linked
1231|                    fields. The first error that occurs in the sequence
1232|                    of updates is the return value.
1233|
1234|   Return Values :  E_OK                - success
1235|                    E_BAD_ARGUMENT      - invalid field pointer
1236|                    E_SYSTEM_ERROR      - some severe basic error
1237+--------------------------------------------------------------------------*/
1238static int
1239Synchronize_Linked_Fields(FIELD *field)
1240{
1241  FIELD *linked_field;
1242  int res = E_OK;
1243  int syncres;
1244
1245  if (!field)
1246    return (E_BAD_ARGUMENT);
1247
1248  if (!field->link)
1249    return (E_SYSTEM_ERROR);
1250
1251  for (linked_field = field->link;
1252       (linked_field != field) && (linked_field != 0);
1253       linked_field = linked_field->link)
1254    {
1255      if (((syncres = Synchronize_Field(linked_field)) != E_OK) &&
1256	  (res == E_OK))
1257	res = syncres;
1258    }
1259  return (res);
1260}
1261
1262/*---------------------------------------------------------------------------
1263|   Facility      :  libnform
1264|   Function      :  int _nc_Synchronize_Attributes(FIELD * field)
1265|
1266|   Description   :  If a fields visual attributes have changed, this
1267|                    routine is called to propagate those changes to the
1268|                    screen.
1269|
1270|   Return Values :  E_OK             - success
1271|                    E_BAD_ARGUMENT   - invalid field pointer
1272|                    E_SYSTEM_ERROR   - some severe basic error
1273+--------------------------------------------------------------------------*/
1274NCURSES_EXPORT(int)
1275_nc_Synchronize_Attributes(FIELD *field)
1276{
1277  FORM *form;
1278  int res = E_OK;
1279  WINDOW *formwin;
1280
1281  T((T_CALLED("_nc_Synchronize_Attributes(%p)"), (void *)field));
1282
1283  if (!field)
1284    returnCode(E_BAD_ARGUMENT);
1285
1286  CHECKPOS(field->form);
1287  if (((form = field->form) != (FORM *)0)
1288      && Field_Really_Appears(field))
1289    {
1290      if (form->current == field)
1291	{
1292	  Synchronize_Buffer(form);
1293	  Set_Field_Window_Attributes(field, form->w);
1294	  werase(form->w);
1295	  wmove(form->w, form->currow, form->curcol);
1296
1297	  if (Field_Has_Option(field, O_PUBLIC))
1298	    {
1299	      if (Justification_Allowed(field))
1300		Undo_Justification(field, form->w);
1301	      else
1302		Buffer_To_Window(field, form->w);
1303	    }
1304	  else
1305	    {
1306	      formwin = Get_Form_Window(form);
1307	      copywin(form->w, formwin,
1308		      0, 0,
1309		      field->frow, field->fcol,
1310		      field->frow + field->rows - 1,
1311		      field->fcol + field->cols - 1, 0);
1312	      wsyncup(formwin);
1313	      Buffer_To_Window(field, form->w);
1314	      SetStatus(field, _NEWTOP);	/* fake refresh to paint all */
1315	      _nc_Refresh_Current_Field(form);
1316	    }
1317	}
1318      else
1319	{
1320	  res = Display_Field(field);
1321	}
1322    }
1323  CHECKPOS(form);
1324  returnCode(res);
1325}
1326
1327/*---------------------------------------------------------------------------
1328|   Facility      :  libnform
1329|   Function      :  int _nc_Synchronize_Options(FIELD * field,
1330|                                                Field_Options newopts)
1331|
1332|   Description   :  If a fields options have changed, this routine is
1333|                    called to propagate these changes to the screen and
1334|                    to really change the behavior of the field.
1335|
1336|   Return Values :  E_OK                - success
1337|                    E_BAD_ARGUMENT      - invalid field pointer
1338|                    E_CURRENT           - field is the current one
1339|                    E_SYSTEM_ERROR      - some severe basic error
1340+--------------------------------------------------------------------------*/
1341NCURSES_EXPORT(int)
1342_nc_Synchronize_Options(FIELD *field, Field_Options newopts)
1343{
1344  Field_Options oldopts;
1345  Field_Options changed_opts;
1346  FORM *form;
1347  int res = E_OK;
1348
1349  T((T_CALLED("_nc_Synchronize_Options(%p,%#x)"), (void *)field, newopts));
1350
1351  if (!field)
1352    returnCode(E_BAD_ARGUMENT);
1353
1354  oldopts = field->opts;
1355  changed_opts = oldopts ^ newopts;
1356  field->opts = newopts;
1357  form = field->form;
1358
1359  if (form)
1360    {
1361      if (form->status & _POSTED)
1362	{
1363	  if (form->current == field)
1364	    {
1365	      field->opts = oldopts;
1366	      returnCode(E_CURRENT);
1367	    }
1368	  if (form->curpage == field->page)
1369	    {
1370	      if ((unsigned)changed_opts & O_VISIBLE)
1371		{
1372		  if ((unsigned)newopts & O_VISIBLE)
1373		    res = Display_Field(field);
1374		  else
1375		    res = Erase_Field(field);
1376		}
1377	      else
1378		{
1379		  if (((unsigned)changed_opts & O_PUBLIC) &&
1380		      ((unsigned)newopts & O_VISIBLE))
1381		    res = Display_Field(field);
1382		}
1383	    }
1384	}
1385    }
1386
1387  if ((unsigned)changed_opts & O_STATIC)
1388    {
1389      bool single_line_field = Single_Line_Field(field);
1390      int res2 = E_OK;
1391
1392      if ((unsigned)newopts & O_STATIC)
1393	{
1394	  /* the field becomes now static */
1395	  ClrStatus(field, _MAY_GROW);
1396	  /* if actually we have no hidden columns, justification may
1397	     occur again */
1398	  if (single_line_field &&
1399	      (field->cols == field->dcols) &&
1400	      (field->just != NO_JUSTIFICATION) &&
1401	      Field_Really_Appears(field))
1402	    {
1403	      res2 = Display_Field(field);
1404	    }
1405	}
1406      else
1407	{
1408	  /* field is no longer static */
1409	  if ((field->maxgrow == 0) ||
1410	      (single_line_field && (field->dcols < field->maxgrow)) ||
1411	      (!single_line_field && (field->drows < field->maxgrow)))
1412	    {
1413	      SetStatus(field, _MAY_GROW);
1414	      /* a field with justification now changes its behavior,
1415	         so we must redisplay it */
1416	      if (single_line_field &&
1417		  (field->just != NO_JUSTIFICATION) &&
1418		  Field_Really_Appears(field))
1419		{
1420		  res2 = Display_Field(field);
1421		}
1422	    }
1423	}
1424      if (res2 != E_OK)
1425	res = res2;
1426    }
1427
1428  returnCode(res);
1429}
1430
1431/*
1432 * Removes the focus from the current field of the form.
1433 */
1434void
1435_nc_Unset_Current_Field(FORM *form)
1436{
1437  FIELD *field = form->current;
1438
1439  _nc_Refresh_Current_Field(form);
1440  if (Field_Has_Option(field, O_PUBLIC))
1441    {
1442      if (field->drows > field->rows)
1443	{
1444	  if (form->toprow == 0)
1445	    ClrStatus(field, _NEWTOP);
1446	  else
1447	    SetStatus(field, _NEWTOP);
1448	}
1449      else
1450	{
1451	  if (Justification_Allowed(field))
1452	    {
1453	      Window_To_Buffer(form, field);
1454	      werase(form->w);
1455	      Perform_Justification(field, form->w);
1456	      if (Field_Has_Option(field, O_DYNAMIC_JUSTIFY) &&
1457		  (form->w->_parent == 0))
1458		{
1459		  copywin(form->w,
1460			  Get_Form_Window(form),
1461			  0,
1462			  0,
1463			  field->frow,
1464			  field->fcol,
1465			  field->frow,
1466			  field->cols + field->fcol - 1,
1467			  0);
1468		  wsyncup(Get_Form_Window(form));
1469		}
1470	      else
1471		{
1472		  wsyncup(form->w);
1473		}
1474	    }
1475	}
1476    }
1477  delwin(form->w);
1478  form->w = (WINDOW *)0;
1479  form->current = 0;
1480}
1481
1482/*---------------------------------------------------------------------------
1483|   Facility      :  libnform
1484|   Function      :  int _nc_Set_Current_Field(FORM  * form,
1485|                                              FIELD * newfield)
1486|
1487|   Description   :  Make the newfield the new current field.
1488|
1489|   Return Values :  E_OK              - success
1490|                    E_BAD_ARGUMENT    - invalid form or field pointer
1491|                    E_SYSTEM_ERROR    - some severe basic error
1492|                    E_NOT_CONNECTED   - no fields are connected to the form
1493+--------------------------------------------------------------------------*/
1494NCURSES_EXPORT(int)
1495_nc_Set_Current_Field(FORM *form, FIELD *newfield)
1496{
1497  FIELD *field;
1498  WINDOW *new_window;
1499
1500  T((T_CALLED("_nc_Set_Current_Field(%p,%p)"), (void *)form, (void *)newfield));
1501
1502  if (!form || !newfield || (newfield->form != form))
1503    returnCode(E_BAD_ARGUMENT);
1504
1505  if ((form->status & _IN_DRIVER))
1506    returnCode(E_BAD_STATE);
1507
1508  if (!(form->field))
1509    returnCode(E_NOT_CONNECTED);
1510
1511  field = form->current;
1512
1513  if ((field != newfield) ||
1514      !(form->status & _POSTED))
1515    {
1516      if (field && (form->w) &&
1517	  (Field_Has_Option(field, O_VISIBLE)) &&
1518	  (field->form->curpage == field->page))
1519	_nc_Unset_Current_Field(form);
1520
1521      field = newfield;
1522
1523      if (Has_Invisible_Parts(field))
1524	new_window = newpad(field->drows, field->dcols);
1525      else
1526	new_window = derwin(Get_Form_Window(form),
1527			    field->rows, field->cols, field->frow, field->fcol);
1528
1529      if (!new_window)
1530	returnCode(E_SYSTEM_ERROR);
1531
1532      form->current = field;
1533
1534      if (form->w)
1535	delwin(form->w);
1536      form->w = new_window;
1537
1538      ClrStatus(form, _WINDOW_MODIFIED);
1539      Set_Field_Window_Attributes(field, form->w);
1540
1541      if (Has_Invisible_Parts(field))
1542	{
1543	  werase(form->w);
1544	  Buffer_To_Window(field, form->w);
1545	}
1546      else
1547	{
1548	  if (Justification_Allowed(field))
1549	    {
1550	      werase(form->w);
1551	      Undo_Justification(field, form->w);
1552	      wsyncup(form->w);
1553	    }
1554	}
1555
1556      untouchwin(form->w);
1557    }
1558
1559  form->currow = form->curcol = form->toprow = form->begincol = 0;
1560  returnCode(E_OK);
1561}
1562
1563/*----------------------------------------------------------------------------
1564  Intra-Field Navigation routines
1565  --------------------------------------------------------------------------*/
1566
1567/*---------------------------------------------------------------------------
1568|   Facility      :  libnform
1569|   Function      :  static int IFN_Next_Character(FORM * form)
1570|
1571|   Description   :  Move to the next character in the field. In a multi-line
1572|                    field this wraps at the end of the line.
1573|
1574|   Return Values :  E_OK                - success
1575|                    E_REQUEST_DENIED    - at the rightmost position
1576+--------------------------------------------------------------------------*/
1577static int
1578IFN_Next_Character(FORM *form)
1579{
1580  FIELD *field = form->current;
1581  int step = myWCWIDTH(form->w, form->currow, form->curcol);
1582
1583  T((T_CALLED("IFN_Next_Character(%p)"), (void *)form));
1584  if ((form->curcol += step) == field->dcols)
1585    {
1586      if ((++(form->currow)) == field->drows)
1587	{
1588#if GROW_IF_NAVIGATE
1589	  if (!Single_Line_Field(field) && Field_Grown(field, 1))
1590	    {
1591	      form->curcol = 0;
1592	      returnCode(E_OK);
1593	    }
1594#endif
1595	  form->currow--;
1596#if GROW_IF_NAVIGATE
1597	  if (Single_Line_Field(field) && Field_Grown(field, 1))
1598	    returnCode(E_OK);
1599#endif
1600	  form->curcol -= step;
1601	  returnCode(E_REQUEST_DENIED);
1602	}
1603      form->curcol = 0;
1604    }
1605  returnCode(E_OK);
1606}
1607
1608/*---------------------------------------------------------------------------
1609|   Facility      :  libnform
1610|   Function      :  static int IFN_Previous_Character(FORM * form)
1611|
1612|   Description   :  Move to the previous character in the field. In a
1613|                    multi-line field this wraps and the beginning of the
1614|                    line.
1615|
1616|   Return Values :  E_OK                - success
1617|                    E_REQUEST_DENIED    - at the leftmost position
1618+--------------------------------------------------------------------------*/
1619static int
1620IFN_Previous_Character(FORM *form)
1621{
1622  int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1623  int oldcol = form->curcol;
1624
1625  T((T_CALLED("IFN_Previous_Character(%p)"), (void *)form));
1626  if ((form->curcol -= amount) < 0)
1627    {
1628      if ((--(form->currow)) < 0)
1629	{
1630	  form->currow++;
1631	  form->curcol = oldcol;
1632	  returnCode(E_REQUEST_DENIED);
1633	}
1634      form->curcol = form->current->dcols - 1;
1635    }
1636  returnCode(E_OK);
1637}
1638
1639/*---------------------------------------------------------------------------
1640|   Facility      :  libnform
1641|   Function      :  static int IFN_Next_Line(FORM * form)
1642|
1643|   Description   :  Move to the beginning of the next line in the field
1644|
1645|   Return Values :  E_OK                - success
1646|                    E_REQUEST_DENIED    - at the last line
1647+--------------------------------------------------------------------------*/
1648static int
1649IFN_Next_Line(FORM *form)
1650{
1651  FIELD *field = form->current;
1652
1653  T((T_CALLED("IFN_Next_Line(%p)"), (void *)form));
1654  if ((++(form->currow)) == field->drows)
1655    {
1656#if GROW_IF_NAVIGATE
1657      if (!Single_Line_Field(field) && Field_Grown(field, 1))
1658	returnCode(E_OK);
1659#endif
1660      form->currow--;
1661      returnCode(E_REQUEST_DENIED);
1662    }
1663  form->curcol = 0;
1664  returnCode(E_OK);
1665}
1666
1667/*---------------------------------------------------------------------------
1668|   Facility      :  libnform
1669|   Function      :  static int IFN_Previous_Line(FORM * form)
1670|
1671|   Description   :  Move to the beginning of the previous line in the field
1672|
1673|   Return Values :  E_OK                - success
1674|                    E_REQUEST_DENIED    - at the first line
1675+--------------------------------------------------------------------------*/
1676static int
1677IFN_Previous_Line(FORM *form)
1678{
1679  T((T_CALLED("IFN_Previous_Line(%p)"), (void *)form));
1680  if ((--(form->currow)) < 0)
1681    {
1682      form->currow++;
1683      returnCode(E_REQUEST_DENIED);
1684    }
1685  form->curcol = 0;
1686  returnCode(E_OK);
1687}
1688
1689/*---------------------------------------------------------------------------
1690|   Facility      :  libnform
1691|   Function      :  static int IFN_Next_Word(FORM * form)
1692|
1693|   Description   :  Move to the beginning of the next word in the field.
1694|
1695|   Return Values :  E_OK             - success
1696|                    E_REQUEST_DENIED - there is no next word
1697+--------------------------------------------------------------------------*/
1698static int
1699IFN_Next_Word(FORM *form)
1700{
1701  FIELD *field = form->current;
1702  FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1703  FIELD_CELL *s;
1704  FIELD_CELL *t;
1705
1706  T((T_CALLED("IFN_Next_Word(%p)"), (void *)form));
1707
1708  /* We really need access to the data, so we have to synchronize */
1709  Synchronize_Buffer(form);
1710
1711  /* Go to the first whitespace after the current position (including
1712     current position). This is then the starting point to look for the
1713     next non-blank data */
1714  s = Get_First_Whitespace_Character(bp, Buffer_Length(field) -
1715				     (int)(bp - field->buf));
1716
1717  /* Find the start of the next word */
1718  t = Get_Start_Of_Data(s, Buffer_Length(field) -
1719			(int)(s - field->buf));
1720#if !FRIENDLY_PREV_NEXT_WORD
1721  if (s == t)
1722    returnCode(E_REQUEST_DENIED);
1723  else
1724#endif
1725    {
1726      Adjust_Cursor_Position(form, t);
1727      returnCode(E_OK);
1728    }
1729}
1730
1731/*---------------------------------------------------------------------------
1732|   Facility      :  libnform
1733|   Function      :  static int IFN_Previous_Word(FORM * form)
1734|
1735|   Description   :  Move to the beginning of the previous word in the field.
1736|
1737|   Return Values :  E_OK             - success
1738|                    E_REQUEST_DENIED - there is no previous word
1739+--------------------------------------------------------------------------*/
1740static int
1741IFN_Previous_Word(FORM *form)
1742{
1743  FIELD *field = form->current;
1744  FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1745  FIELD_CELL *s;
1746  FIELD_CELL *t;
1747  bool again = FALSE;
1748
1749  T((T_CALLED("IFN_Previous_Word(%p)"), (void *)form));
1750
1751  /* We really need access to the data, so we have to synchronize */
1752  Synchronize_Buffer(form);
1753
1754  s = After_End_Of_Data(field->buf, (int)(bp - field->buf));
1755  /* s points now right after the last non-blank in the buffer before bp.
1756     If bp was in a word, s equals bp. In this case we must find the last
1757     whitespace in the buffer before bp and repeat the game to really find
1758     the previous word! */
1759  if (s == bp)
1760    again = TRUE;
1761
1762  /* And next call now goes backward to look for the last whitespace
1763     before that, pointing right after this, so it points to the begin
1764     of the previous word.
1765   */
1766  t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1767#if !FRIENDLY_PREV_NEXT_WORD
1768  if (s == t)
1769    returnCode(E_REQUEST_DENIED);
1770#endif
1771  if (again)
1772    {
1773      /* and do it again, replacing bp by t */
1774      s = After_End_Of_Data(field->buf, (int)(t - field->buf));
1775      t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1776#if !FRIENDLY_PREV_NEXT_WORD
1777      if (s == t)
1778	returnCode(E_REQUEST_DENIED);
1779#endif
1780    }
1781  Adjust_Cursor_Position(form, t);
1782  returnCode(E_OK);
1783}
1784
1785/*---------------------------------------------------------------------------
1786|   Facility      :  libnform
1787|   Function      :  static int IFN_Beginning_Of_Field(FORM * form)
1788|
1789|   Description   :  Place the cursor at the first non-pad character in
1790|                    the field.
1791|
1792|   Return Values :  E_OK             - success
1793+--------------------------------------------------------------------------*/
1794static int
1795IFN_Beginning_Of_Field(FORM *form)
1796{
1797  FIELD *field = form->current;
1798
1799  T((T_CALLED("IFN_Beginning_Of_Field(%p)"), (void *)form));
1800  Synchronize_Buffer(form);
1801  Adjust_Cursor_Position(form,
1802			 Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1803  returnCode(E_OK);
1804}
1805
1806/*---------------------------------------------------------------------------
1807|   Facility      :  libnform
1808|   Function      :  static int IFN_End_Of_Field(FORM * form)
1809|
1810|   Description   :  Place the cursor after the last non-pad character in
1811|                    the field. If the field occupies the last position in
1812|                    the buffer, the cursor is positioned on the last
1813|                    character.
1814|
1815|   Return Values :  E_OK              - success
1816+--------------------------------------------------------------------------*/
1817static int
1818IFN_End_Of_Field(FORM *form)
1819{
1820  FIELD *field = form->current;
1821  FIELD_CELL *pos;
1822
1823  T((T_CALLED("IFN_End_Of_Field(%p)"), (void *)form));
1824  Synchronize_Buffer(form);
1825  pos = After_End_Of_Data(field->buf, Buffer_Length(field));
1826  if (pos == (field->buf + Buffer_Length(field)))
1827    pos--;
1828  Adjust_Cursor_Position(form, pos);
1829  returnCode(E_OK);
1830}
1831
1832/*---------------------------------------------------------------------------
1833|   Facility      :  libnform
1834|   Function      :  static int IFN_Beginning_Of_Line(FORM * form)
1835|
1836|   Description   :  Place the cursor on the first non-pad character in
1837|                    the current line of the field.
1838|
1839|   Return Values :  E_OK         - success
1840+--------------------------------------------------------------------------*/
1841static int
1842IFN_Beginning_Of_Line(FORM *form)
1843{
1844  FIELD *field = form->current;
1845
1846  T((T_CALLED("IFN_Beginning_Of_Line(%p)"), (void *)form));
1847  Synchronize_Buffer(form);
1848  Adjust_Cursor_Position(form,
1849			 Get_Start_Of_Data(Address_Of_Current_Row_In_Buffer(form),
1850					   field->dcols));
1851  returnCode(E_OK);
1852}
1853
1854/*---------------------------------------------------------------------------
1855|   Facility      :  libnform
1856|   Function      :  static int IFN_End_Of_Line(FORM * form)
1857|
1858|   Description   :  Place the cursor after the last non-pad character in the
1859|                    current line of the field. If the field occupies the
1860|                    last column in the line, the cursor is positioned on the
1861|                    last character of the line.
1862|
1863|   Return Values :  E_OK        - success
1864+--------------------------------------------------------------------------*/
1865static int
1866IFN_End_Of_Line(FORM *form)
1867{
1868  FIELD *field = form->current;
1869  FIELD_CELL *pos;
1870  FIELD_CELL *bp;
1871
1872  T((T_CALLED("IFN_End_Of_Line(%p)"), (void *)form));
1873  Synchronize_Buffer(form);
1874  bp = Address_Of_Current_Row_In_Buffer(form);
1875  pos = After_End_Of_Data(bp, field->dcols);
1876  if (pos == (bp + field->dcols))
1877    pos--;
1878  Adjust_Cursor_Position(form, pos);
1879  returnCode(E_OK);
1880}
1881
1882/*---------------------------------------------------------------------------
1883|   Facility      :  libnform
1884|   Function      :  static int IFN_Left_Character(FORM * form)
1885|
1886|   Description   :  Move one character to the left in the current line.
1887|                    This doesn't cycle.
1888|
1889|   Return Values :  E_OK             - success
1890|                    E_REQUEST_DENIED - already in first column
1891+--------------------------------------------------------------------------*/
1892static int
1893IFN_Left_Character(FORM *form)
1894{
1895  int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1896  int oldcol = form->curcol;
1897
1898  T((T_CALLED("IFN_Left_Character(%p)"), (void *)form));
1899  if ((form->curcol -= amount) < 0)
1900    {
1901      form->curcol = oldcol;
1902      returnCode(E_REQUEST_DENIED);
1903    }
1904  returnCode(E_OK);
1905}
1906
1907/*---------------------------------------------------------------------------
1908|   Facility      :  libnform
1909|   Function      :  static int IFN_Right_Character(FORM * form)
1910|
1911|   Description   :  Move one character to the right in the current line.
1912|                    This doesn't cycle.
1913|
1914|   Return Values :  E_OK              - success
1915|                    E_REQUEST_DENIED  - already in last column
1916+--------------------------------------------------------------------------*/
1917static int
1918IFN_Right_Character(FORM *form)
1919{
1920  int amount = myWCWIDTH(form->w, form->currow, form->curcol);
1921  int oldcol = form->curcol;
1922
1923  T((T_CALLED("IFN_Right_Character(%p)"), (void *)form));
1924  if ((form->curcol += amount) >= form->current->dcols)
1925    {
1926#if GROW_IF_NAVIGATE
1927      FIELD *field = form->current;
1928
1929      if (Single_Line_Field(field) && Field_Grown(field, 1))
1930	returnCode(E_OK);
1931#endif
1932      form->curcol = oldcol;
1933      returnCode(E_REQUEST_DENIED);
1934    }
1935  returnCode(E_OK);
1936}
1937
1938/*---------------------------------------------------------------------------
1939|   Facility      :  libnform
1940|   Function      :  static int IFN_Up_Character(FORM * form)
1941|
1942|   Description   :  Move one line up. This doesn't cycle through the lines
1943|                    of the field.
1944|
1945|   Return Values :  E_OK              - success
1946|                    E_REQUEST_DENIED  - already in last column
1947+--------------------------------------------------------------------------*/
1948static int
1949IFN_Up_Character(FORM *form)
1950{
1951  T((T_CALLED("IFN_Up_Character(%p)"), (void *)form));
1952  if ((--(form->currow)) < 0)
1953    {
1954      form->currow++;
1955      returnCode(E_REQUEST_DENIED);
1956    }
1957  returnCode(E_OK);
1958}
1959
1960/*---------------------------------------------------------------------------
1961|   Facility      :  libnform
1962|   Function      :  static int IFN_Down_Character(FORM * form)
1963|
1964|   Description   :  Move one line down. This doesn't cycle through the
1965|                    lines of the field.
1966|
1967|   Return Values :  E_OK              - success
1968|                    E_REQUEST_DENIED  - already in last column
1969+--------------------------------------------------------------------------*/
1970static int
1971IFN_Down_Character(FORM *form)
1972{
1973  FIELD *field = form->current;
1974
1975  T((T_CALLED("IFN_Down_Character(%p)"), (void *)form));
1976  if ((++(form->currow)) == field->drows)
1977    {
1978#if GROW_IF_NAVIGATE
1979      if (!Single_Line_Field(field) && Field_Grown(field, 1))
1980	returnCode(E_OK);
1981#endif
1982      --(form->currow);
1983      returnCode(E_REQUEST_DENIED);
1984    }
1985  returnCode(E_OK);
1986}
1987/*----------------------------------------------------------------------------
1988  END of Intra-Field Navigation routines
1989  --------------------------------------------------------------------------*/
1990
1991/*----------------------------------------------------------------------------
1992  Vertical scrolling helper routines
1993  --------------------------------------------------------------------------*/
1994
1995/*---------------------------------------------------------------------------
1996|   Facility      :  libnform
1997|   Function      :  static int VSC_Generic(FORM *form, int nlines)
1998|
1999|   Description   :  Scroll multi-line field forward (nlines>0) or
2000|                    backward (nlines<0) this many lines.
2001|
2002|   Return Values :  E_OK              - success
2003|                    E_REQUEST_DENIED  - can't scroll
2004+--------------------------------------------------------------------------*/
2005static int
2006VSC_Generic(FORM *form, int nlines)
2007{
2008  FIELD *field = form->current;
2009  int res = E_REQUEST_DENIED;
2010  int rows_to_go = (nlines > 0 ? nlines : -nlines);
2011
2012  if (nlines > 0)
2013    {
2014      if ((rows_to_go + form->toprow) > (field->drows - field->rows))
2015	rows_to_go = (field->drows - field->rows - form->toprow);
2016
2017      if (rows_to_go > 0)
2018	{
2019	  form->currow += rows_to_go;
2020	  form->toprow += rows_to_go;
2021	  res = E_OK;
2022	}
2023    }
2024  else
2025    {
2026      if (rows_to_go > form->toprow)
2027	rows_to_go = form->toprow;
2028
2029      if (rows_to_go > 0)
2030	{
2031	  form->currow -= rows_to_go;
2032	  form->toprow -= rows_to_go;
2033	  res = E_OK;
2034	}
2035    }
2036  return (res);
2037}
2038/*----------------------------------------------------------------------------
2039  End of Vertical scrolling helper routines
2040  --------------------------------------------------------------------------*/
2041
2042/*----------------------------------------------------------------------------
2043  Vertical scrolling routines
2044  --------------------------------------------------------------------------*/
2045
2046/*---------------------------------------------------------------------------
2047|   Facility      :  libnform
2048|   Function      :  static int Vertical_Scrolling(
2049|                                           int (* const fct) (FORM *),
2050|                                           FORM * form)
2051|
2052|   Description   :  Performs the generic vertical scrolling routines.
2053|                    This has to check for a multi-line field and to set
2054|                    the _NEWTOP flag if scrolling really occurred.
2055|
2056|   Return Values :  Propagated error code from low-level driver calls
2057+--------------------------------------------------------------------------*/
2058static int
2059Vertical_Scrolling(int (*const fct) (FORM *), FORM *form)
2060{
2061  int res = E_REQUEST_DENIED;
2062
2063  if (!Single_Line_Field(form->current))
2064    {
2065      res = fct(form);
2066      if (res == E_OK)
2067	SetStatus(form->current, _NEWTOP);
2068    }
2069  return (res);
2070}
2071
2072/*---------------------------------------------------------------------------
2073|   Facility      :  libnform
2074|   Function      :  static int VSC_Scroll_Line_Forward(FORM * form)
2075|
2076|   Description   :  Scroll multi-line field forward a line
2077|
2078|   Return Values :  E_OK                - success
2079|                    E_REQUEST_DENIED    - no data ahead
2080+--------------------------------------------------------------------------*/
2081static int
2082VSC_Scroll_Line_Forward(FORM *form)
2083{
2084  T((T_CALLED("VSC_Scroll_Line_Forward(%p)"), (void *)form));
2085  returnCode(VSC_Generic(form, 1));
2086}
2087
2088/*---------------------------------------------------------------------------
2089|   Facility      :  libnform
2090|   Function      :  static int VSC_Scroll_Line_Backward(FORM * form)
2091|
2092|   Description   :  Scroll multi-line field backward a line
2093|
2094|   Return Values :  E_OK                - success
2095|                    E_REQUEST_DENIED    - no data behind
2096+--------------------------------------------------------------------------*/
2097static int
2098VSC_Scroll_Line_Backward(FORM *form)
2099{
2100  T((T_CALLED("VSC_Scroll_Line_Backward(%p)"), (void *)form));
2101  returnCode(VSC_Generic(form, -1));
2102}
2103
2104/*---------------------------------------------------------------------------
2105|   Facility      :  libnform
2106|   Function      :  static int VSC_Scroll_Page_Forward(FORM * form)
2107|
2108|   Description   :  Scroll a multi-line field forward a page
2109|
2110|   Return Values :  E_OK              - success
2111|                    E_REQUEST_DENIED  - no data ahead
2112+--------------------------------------------------------------------------*/
2113static int
2114VSC_Scroll_Page_Forward(FORM *form)
2115{
2116  T((T_CALLED("VSC_Scroll_Page_Forward(%p)"), (void *)form));
2117  returnCode(VSC_Generic(form, form->current->rows));
2118}
2119
2120/*---------------------------------------------------------------------------
2121|   Facility      :  libnform
2122|   Function      :  static int VSC_Scroll_Half_Page_Forward(FORM * form)
2123|
2124|   Description   :  Scroll a multi-line field forward half a page
2125|
2126|   Return Values :  E_OK              - success
2127|                    E_REQUEST_DENIED  - no data ahead
2128+--------------------------------------------------------------------------*/
2129static int
2130VSC_Scroll_Half_Page_Forward(FORM *form)
2131{
2132  T((T_CALLED("VSC_Scroll_Half_Page_Forward(%p)"), (void *)form));
2133  returnCode(VSC_Generic(form, (form->current->rows + 1) / 2));
2134}
2135
2136/*---------------------------------------------------------------------------
2137|   Facility      :  libnform
2138|   Function      :  static int VSC_Scroll_Page_Backward(FORM * form)
2139|
2140|   Description   :  Scroll a multi-line field backward a page
2141|
2142|   Return Values :  E_OK              - success
2143|                    E_REQUEST_DENIED  - no data behind
2144+--------------------------------------------------------------------------*/
2145static int
2146VSC_Scroll_Page_Backward(FORM *form)
2147{
2148  T((T_CALLED("VSC_Scroll_Page_Backward(%p)"), (void *)form));
2149  returnCode(VSC_Generic(form, -(form->current->rows)));
2150}
2151
2152/*---------------------------------------------------------------------------
2153|   Facility      :  libnform
2154|   Function      :  static int VSC_Scroll_Half_Page_Backward(FORM * form)
2155|
2156|   Description   :  Scroll a multi-line field backward half a page
2157|
2158|   Return Values :  E_OK              - success
2159|                    E_REQUEST_DENIED  - no data behind
2160+--------------------------------------------------------------------------*/
2161static int
2162VSC_Scroll_Half_Page_Backward(FORM *form)
2163{
2164  T((T_CALLED("VSC_Scroll_Half_Page_Backward(%p)"), (void *)form));
2165  returnCode(VSC_Generic(form, -((form->current->rows + 1) / 2)));
2166}
2167/*----------------------------------------------------------------------------
2168  End of Vertical scrolling routines
2169  --------------------------------------------------------------------------*/
2170
2171/*----------------------------------------------------------------------------
2172  Horizontal scrolling helper routines
2173  --------------------------------------------------------------------------*/
2174
2175/*---------------------------------------------------------------------------
2176|   Facility      :  libnform
2177|   Function      :  static int HSC_Generic(FORM *form, int ncolumns)
2178|
2179|   Description   :  Scroll single-line field forward (ncolumns>0) or
2180|                    backward (ncolumns<0) this many columns.
2181|
2182|   Return Values :  E_OK              - success
2183|                    E_REQUEST_DENIED  - can't scroll
2184+--------------------------------------------------------------------------*/
2185static int
2186HSC_Generic(FORM *form, int ncolumns)
2187{
2188  FIELD *field = form->current;
2189  int res = E_REQUEST_DENIED;
2190  int cols_to_go = (ncolumns > 0 ? ncolumns : -ncolumns);
2191
2192  if (ncolumns > 0)
2193    {
2194      if ((cols_to_go + form->begincol) > (field->dcols - field->cols))
2195	cols_to_go = field->dcols - field->cols - form->begincol;
2196
2197      if (cols_to_go > 0)
2198	{
2199	  form->curcol += cols_to_go;
2200	  form->begincol += cols_to_go;
2201	  res = E_OK;
2202	}
2203    }
2204  else
2205    {
2206      if (cols_to_go > form->begincol)
2207	cols_to_go = form->begincol;
2208
2209      if (cols_to_go > 0)
2210	{
2211	  form->curcol -= cols_to_go;
2212	  form->begincol -= cols_to_go;
2213	  res = E_OK;
2214	}
2215    }
2216  return (res);
2217}
2218/*----------------------------------------------------------------------------
2219  End of Horizontal scrolling helper routines
2220  --------------------------------------------------------------------------*/
2221
2222/*----------------------------------------------------------------------------
2223  Horizontal scrolling routines
2224  --------------------------------------------------------------------------*/
2225
2226/*---------------------------------------------------------------------------
2227|   Facility      :  libnform
2228|   Function      :  static int Horizontal_Scrolling(
2229|                                          int (* const fct) (FORM *),
2230|                                          FORM * form)
2231|
2232|   Description   :  Performs the generic horizontal scrolling routines.
2233|                    This has to check for a single-line field.
2234|
2235|   Return Values :  Propagated error code from low-level driver calls
2236+--------------------------------------------------------------------------*/
2237static int
2238Horizontal_Scrolling(int (*const fct) (FORM *), FORM *form)
2239{
2240  if (Single_Line_Field(form->current))
2241    return fct(form);
2242  else
2243    return (E_REQUEST_DENIED);
2244}
2245
2246/*---------------------------------------------------------------------------
2247|   Facility      :  libnform
2248|   Function      :  static int HSC_Scroll_Char_Forward(FORM * form)
2249|
2250|   Description   :  Scroll single-line field forward a character
2251|
2252|   Return Values :  E_OK                - success
2253|                    E_REQUEST_DENIED    - no data ahead
2254+--------------------------------------------------------------------------*/
2255static int
2256HSC_Scroll_Char_Forward(FORM *form)
2257{
2258  T((T_CALLED("HSC_Scroll_Char_Forward(%p)"), (void *)form));
2259  returnCode(HSC_Generic(form, 1));
2260}
2261
2262/*---------------------------------------------------------------------------
2263|   Facility      :  libnform
2264|   Function      :  static int HSC_Scroll_Char_Backward(FORM * form)
2265|
2266|   Description   :  Scroll single-line field backward a character
2267|
2268|   Return Values :  E_OK                - success
2269|                    E_REQUEST_DENIED    - no data behind
2270+--------------------------------------------------------------------------*/
2271static int
2272HSC_Scroll_Char_Backward(FORM *form)
2273{
2274  T((T_CALLED("HSC_Scroll_Char_Backward(%p)"), (void *)form));
2275  returnCode(HSC_Generic(form, -1));
2276}
2277
2278/*---------------------------------------------------------------------------
2279|   Facility      :  libnform
2280|   Function      :  static int HSC_Horizontal_Line_Forward(FORM* form)
2281|
2282|   Description   :  Scroll single-line field forward a line
2283|
2284|   Return Values :  E_OK                - success
2285|                    E_REQUEST_DENIED    - no data ahead
2286+--------------------------------------------------------------------------*/
2287static int
2288HSC_Horizontal_Line_Forward(FORM *form)
2289{
2290  T((T_CALLED("HSC_Horizontal_Line_Forward(%p)"), (void *)form));
2291  returnCode(HSC_Generic(form, form->current->cols));
2292}
2293
2294/*---------------------------------------------------------------------------
2295|   Facility      :  libnform
2296|   Function      :  static int HSC_Horizontal_Half_Line_Forward(FORM* form)
2297|
2298|   Description   :  Scroll single-line field forward half a line
2299|
2300|   Return Values :  E_OK               - success
2301|                    E_REQUEST_DENIED   - no data ahead
2302+--------------------------------------------------------------------------*/
2303static int
2304HSC_Horizontal_Half_Line_Forward(FORM *form)
2305{
2306  T((T_CALLED("HSC_Horizontal_Half_Line_Forward(%p)"), (void *)form));
2307  returnCode(HSC_Generic(form, (form->current->cols + 1) / 2));
2308}
2309
2310/*---------------------------------------------------------------------------
2311|   Facility      :  libnform
2312|   Function      :  static int HSC_Horizontal_Line_Backward(FORM* form)
2313|
2314|   Description   :  Scroll single-line field backward a line
2315|
2316|   Return Values :  E_OK                - success
2317|                    E_REQUEST_DENIED    - no data behind
2318+--------------------------------------------------------------------------*/
2319static int
2320HSC_Horizontal_Line_Backward(FORM *form)
2321{
2322  T((T_CALLED("HSC_Horizontal_Line_Backward(%p)"), (void *)form));
2323  returnCode(HSC_Generic(form, -(form->current->cols)));
2324}
2325
2326/*---------------------------------------------------------------------------
2327|   Facility      :  libnform
2328|   Function      :  static int HSC_Horizontal_Half_Line_Backward(FORM* form)
2329|
2330|   Description   :  Scroll single-line field backward half a line
2331|
2332|   Return Values :  E_OK                - success
2333|                    E_REQUEST_DENIED    - no data behind
2334+--------------------------------------------------------------------------*/
2335static int
2336HSC_Horizontal_Half_Line_Backward(FORM *form)
2337{
2338  T((T_CALLED("HSC_Horizontal_Half_Line_Backward(%p)"), (void *)form));
2339  returnCode(HSC_Generic(form, -((form->current->cols + 1) / 2)));
2340}
2341
2342/*----------------------------------------------------------------------------
2343  End of Horizontal scrolling routines
2344  --------------------------------------------------------------------------*/
2345
2346/*----------------------------------------------------------------------------
2347  Helper routines for Field Editing
2348  --------------------------------------------------------------------------*/
2349
2350/*---------------------------------------------------------------------------
2351|   Facility      :  libnform
2352|   Function      :  static bool Is_There_Room_For_A_Line(FORM * form)
2353|
2354|   Description   :  Check whether or not there is enough room in the
2355|                    buffer to enter a whole line.
2356|
2357|   Return Values :  TRUE   - there is enough space
2358|                    FALSE  - there is not enough space
2359+--------------------------------------------------------------------------*/
2360NCURSES_INLINE static bool
2361Is_There_Room_For_A_Line(FORM *form)
2362{
2363  FIELD *field = form->current;
2364  FIELD_CELL *begin_of_last_line, *s;
2365
2366  Synchronize_Buffer(form);
2367  begin_of_last_line = Address_Of_Row_In_Buffer(field, (field->drows - 1));
2368  s = After_End_Of_Data(begin_of_last_line, field->dcols);
2369  return ((s == begin_of_last_line) ? TRUE : FALSE);
2370}
2371
2372/*---------------------------------------------------------------------------
2373|   Facility      :  libnform
2374|   Function      :  static bool Is_There_Room_For_A_Char_In_Line(FORM * form)
2375|
2376|   Description   :  Checks whether or not there is room for a new character
2377|                    in the current line.
2378|
2379|   Return Values :  TRUE    - there is room
2380|                    FALSE   - there is not enough room (line full)
2381+--------------------------------------------------------------------------*/
2382NCURSES_INLINE static bool
2383Is_There_Room_For_A_Char_In_Line(FORM *form)
2384{
2385  int last_char_in_line;
2386
2387  wmove(form->w, form->currow, form->current->dcols - 1);
2388  last_char_in_line = (int)(winch(form->w) & A_CHARTEXT);
2389  wmove(form->w, form->currow, form->curcol);
2390  return (((last_char_in_line == form->current->pad) ||
2391	   is_blank(last_char_in_line)) ? TRUE : FALSE);
2392}
2393
2394#define There_Is_No_Room_For_A_Char_In_Line(f) \
2395  !Is_There_Room_For_A_Char_In_Line(f)
2396
2397/*---------------------------------------------------------------------------
2398|   Facility      :  libnform
2399|   Function      :  static int Insert_String(
2400|                                             FORM * form,
2401|                                             int row,
2402|                                             char *txt,
2403|                                             int  len )
2404|
2405|   Description   :  Insert the 'len' characters beginning at pointer 'txt'
2406|                    into the 'row' of the 'form'. The insertion occurs
2407|                    on the beginning of the row, all other characters are
2408|                    moved to the right. After the text a pad character will
2409|                    be inserted to separate the text from the rest. If
2410|                    necessary the insertion moves characters on the next
2411|                    line to make place for the requested insertion string.
2412|
2413|   Return Values :  E_OK              - success
2414|                    E_REQUEST_DENIED  -
2415|                    E_SYSTEM_ERROR    - system error
2416+--------------------------------------------------------------------------*/
2417static int
2418Insert_String(FORM *form, int row, FIELD_CELL *txt, int len)
2419{
2420  FIELD *field = form->current;
2421  FIELD_CELL *bp = Address_Of_Row_In_Buffer(field, row);
2422  int datalen = (int)(After_End_Of_Data(bp, field->dcols) - bp);
2423  int freelen = field->dcols - datalen;
2424  int requiredlen = len + 1;
2425  FIELD_CELL *split;
2426  int result = E_REQUEST_DENIED;
2427
2428  if (freelen >= requiredlen)
2429    {
2430      wmove(form->w, row, 0);
2431      myINSNSTR(form->w, txt, len);
2432      wmove(form->w, row, len);
2433      myINSNSTR(form->w, &myBLANK, 1);
2434      return E_OK;
2435    }
2436  else
2437    {
2438      /* we have to move characters on the next line. If we are on the
2439         last line this may work, if the field is growable */
2440      if ((row == (field->drows - 1)) && Growable(field))
2441	{
2442	  if (!Field_Grown(field, 1))
2443	    return (E_SYSTEM_ERROR);
2444	  /* !!!Side-Effect : might be changed due to growth!!! */
2445	  bp = Address_Of_Row_In_Buffer(field, row);
2446	}
2447
2448      if (row < (field->drows - 1))
2449	{
2450	  split =
2451	    After_Last_Whitespace_Character(bp,
2452					    (int)(Get_Start_Of_Data(bp
2453								    + field->dcols
2454								    - requiredlen,
2455								    requiredlen)
2456						  - bp));
2457	  /* split points now to the first character of the portion of the
2458	     line that must be moved to the next line */
2459	  datalen = (int)(split - bp);	/* + freelen has to stay on this line   */
2460	  freelen = field->dcols - (datalen + freelen);		/* for the next line */
2461
2462	  if ((result = Insert_String(form, row + 1, split, freelen)) == E_OK)
2463	    {
2464	      wmove(form->w, row, datalen);
2465	      wclrtoeol(form->w);
2466	      wmove(form->w, row, 0);
2467	      myINSNSTR(form->w, txt, len);
2468	      wmove(form->w, row, len);
2469	      myINSNSTR(form->w, &myBLANK, 1);
2470	      return E_OK;
2471	    }
2472	}
2473      return (result);
2474    }
2475}
2476
2477/*---------------------------------------------------------------------------
2478|   Facility      :  libnform
2479|   Function      :  static int Wrapping_Not_Necessary_Or_Wrapping_Ok(
2480|                                             FORM * form)
2481|
2482|   Description   :  If a character has been entered into a field, it may
2483|                    be that wrapping has to occur. This routine checks
2484|                    whether or not wrapping is required and if so, performs
2485|                    the wrapping.
2486|
2487|   Return Values :  E_OK              - no wrapping required or wrapping
2488|                                        was successful
2489|                    E_REQUEST_DENIED  -
2490|                    E_SYSTEM_ERROR    - some system error
2491+--------------------------------------------------------------------------*/
2492static int
2493Wrapping_Not_Necessary_Or_Wrapping_Ok(FORM *form)
2494{
2495  FIELD *field = form->current;
2496  int result = E_REQUEST_DENIED;
2497  bool Last_Row = ((field->drows - 1) == form->currow);
2498
2499  if ((Field_Has_Option(field, O_WRAP)) &&	/* wrapping wanted     */
2500      (!Single_Line_Field(field)) &&	/* must be multi-line  */
2501      (There_Is_No_Room_For_A_Char_In_Line(form)) &&	/* line is full        */
2502      (!Last_Row || Growable(field)))	/* there are more lines */
2503    {
2504      FIELD_CELL *bp;
2505      FIELD_CELL *split;
2506      int chars_to_be_wrapped;
2507      int chars_to_remain_on_line;
2508
2509      if (Last_Row)
2510	{
2511	  /* the above logic already ensures, that in this case the field
2512	     is growable */
2513	  if (!Field_Grown(field, 1))
2514	    return E_SYSTEM_ERROR;
2515	}
2516      bp = Address_Of_Current_Row_In_Buffer(form);
2517      Window_To_Buffer(form, field);
2518      split = After_Last_Whitespace_Character(bp, field->dcols);
2519      /* split points to the first character of the sequence to be brought
2520         on the next line */
2521      chars_to_remain_on_line = (int)(split - bp);
2522      chars_to_be_wrapped = field->dcols - chars_to_remain_on_line;
2523      if (chars_to_remain_on_line > 0)
2524	{
2525	  if ((result = Insert_String(form, form->currow + 1, split,
2526				      chars_to_be_wrapped)) == E_OK)
2527	    {
2528	      wmove(form->w, form->currow, chars_to_remain_on_line);
2529	      wclrtoeol(form->w);
2530	      if (form->curcol >= chars_to_remain_on_line)
2531		{
2532		  form->currow++;
2533		  form->curcol -= chars_to_remain_on_line;
2534		}
2535	      return E_OK;
2536	    }
2537	}
2538      else
2539	return E_OK;
2540      if (result != E_OK)
2541	{
2542	  DeleteChar(form);
2543	  Window_To_Buffer(form, field);
2544	  result = E_REQUEST_DENIED;
2545	}
2546    }
2547  else
2548    result = E_OK;		/* wrapping was not necessary */
2549  return (result);
2550}
2551
2552/*----------------------------------------------------------------------------
2553  Field Editing routines
2554  --------------------------------------------------------------------------*/
2555
2556/*---------------------------------------------------------------------------
2557|   Facility      :  libnform
2558|   Function      :  static int Field_Editing(
2559|                                    int (* const fct) (FORM *),
2560|                                    FORM * form)
2561|
2562|   Description   :  Generic routine for field editing requests. The driver
2563|                    routines are only called for editable fields, the
2564|                    _WINDOW_MODIFIED flag is set if editing occurred.
2565|                    This is somewhat special due to the overload semantics
2566|                    of the NEW_LINE and DEL_PREV requests.
2567|
2568|   Return Values :  Error code from low level drivers.
2569+--------------------------------------------------------------------------*/
2570static int
2571Field_Editing(int (*const fct) (FORM *), FORM *form)
2572{
2573  int res = E_REQUEST_DENIED;
2574
2575  /* We have to deal here with the specific case of the overloaded
2576     behavior of New_Line and Delete_Previous requests.
2577     They may end up in navigational requests if we are on the first
2578     character in a field. But navigation is also allowed on non-
2579     editable fields.
2580   */
2581  if ((fct == FE_Delete_Previous) &&
2582      ((unsigned)form->opts & O_BS_OVERLOAD) &&
2583      First_Position_In_Current_Field(form))
2584    {
2585      res = Inter_Field_Navigation(FN_Previous_Field, form);
2586    }
2587  else
2588    {
2589      if (fct == FE_New_Line)
2590	{
2591	  if (((unsigned)form->opts & O_NL_OVERLOAD) &&
2592	      First_Position_In_Current_Field(form))
2593	    {
2594	      res = Inter_Field_Navigation(FN_Next_Field, form);
2595	    }
2596	  else
2597	    /* FE_New_Line deals itself with the _WINDOW_MODIFIED flag */
2598	    res = fct(form);
2599	}
2600      else
2601	{
2602	  /* From now on, everything must be editable */
2603	  if ((unsigned)form->current->opts & O_EDIT)
2604	    {
2605	      res = fct(form);
2606	      if (res == E_OK)
2607		SetStatus(form, _WINDOW_MODIFIED);
2608	    }
2609	}
2610    }
2611  return res;
2612}
2613
2614/*---------------------------------------------------------------------------
2615|   Facility      :  libnform
2616|   Function      :  static int FE_New_Line(FORM * form)
2617|
2618|   Description   :  Perform a new line request. This is rather complex
2619|                    compared to other routines in this code due to the
2620|                    rather difficult to understand description in the
2621|                    manuals.
2622|
2623|   Return Values :  E_OK               - success
2624|                    E_REQUEST_DENIED   - new line not allowed
2625|                    E_SYSTEM_ERROR     - system error
2626+--------------------------------------------------------------------------*/
2627static int
2628FE_New_Line(FORM *form)
2629{
2630  FIELD *field = form->current;
2631  FIELD_CELL *bp, *t;
2632  bool Last_Row = ((field->drows - 1) == form->currow);
2633
2634  T((T_CALLED("FE_New_Line(%p)"), (void *)form));
2635  if (form->status & _OVLMODE)
2636    {
2637      if (Last_Row &&
2638	  (!(Growable(field) && !Single_Line_Field(field))))
2639	{
2640	  if (!((unsigned)form->opts & O_NL_OVERLOAD))
2641	    returnCode(E_REQUEST_DENIED);
2642	  wmove(form->w, form->currow, form->curcol);
2643	  wclrtoeol(form->w);
2644	  /* we have to set this here, although it is also
2645	     handled in the generic routine. The reason is,
2646	     that FN_Next_Field may fail, but the form is
2647	     definitively changed */
2648	  SetStatus(form, _WINDOW_MODIFIED);
2649	  returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2650	}
2651      else
2652	{
2653	  if (Last_Row && !Field_Grown(field, 1))
2654	    {
2655	      /* N.B.: due to the logic in the 'if', LastRow==TRUE
2656	         means here that the field is growable and not
2657	         a single-line field */
2658	      returnCode(E_SYSTEM_ERROR);
2659	    }
2660	  wmove(form->w, form->currow, form->curcol);
2661	  wclrtoeol(form->w);
2662	  form->currow++;
2663	  form->curcol = 0;
2664	  SetStatus(form, _WINDOW_MODIFIED);
2665	  returnCode(E_OK);
2666	}
2667    }
2668  else
2669    {
2670      /* Insert Mode */
2671      if (Last_Row &&
2672	  !(Growable(field) && !Single_Line_Field(field)))
2673	{
2674	  if (!((unsigned)form->opts & O_NL_OVERLOAD))
2675	    returnCode(E_REQUEST_DENIED);
2676	  returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2677	}
2678      else
2679	{
2680	  bool May_Do_It = !Last_Row && Is_There_Room_For_A_Line(form);
2681
2682	  if (!(May_Do_It || Growable(field)))
2683	    returnCode(E_REQUEST_DENIED);
2684	  if (!May_Do_It && !Field_Grown(field, 1))
2685	    returnCode(E_SYSTEM_ERROR);
2686
2687	  bp = Address_Of_Current_Position_In_Buffer(form);
2688	  t = After_End_Of_Data(bp, field->dcols - form->curcol);
2689	  wmove(form->w, form->currow, form->curcol);
2690	  wclrtoeol(form->w);
2691	  form->currow++;
2692	  form->curcol = 0;
2693	  wmove(form->w, form->currow, form->curcol);
2694	  winsertln(form->w);
2695	  myADDNSTR(form->w, bp, (int)(t - bp));
2696	  SetStatus(form, _WINDOW_MODIFIED);
2697	  returnCode(E_OK);
2698	}
2699    }
2700}
2701
2702/*---------------------------------------------------------------------------
2703|   Facility      :  libnform
2704|   Function      :  static int FE_Insert_Character(FORM * form)
2705|
2706|   Description   :  Insert blank character at the cursor position
2707|
2708|   Return Values :  E_OK
2709|                    E_REQUEST_DENIED
2710+--------------------------------------------------------------------------*/
2711static int
2712FE_Insert_Character(FORM *form)
2713{
2714  FIELD *field = form->current;
2715  int result = E_REQUEST_DENIED;
2716
2717  T((T_CALLED("FE_Insert_Character(%p)"), (void *)form));
2718  if (Check_Char(form, field, field->type, (int)C_BLANK,
2719		 (TypeArgument *)(field->arg)))
2720    {
2721      bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
2722
2723      if (There_Is_Room ||
2724	  ((Single_Line_Field(field) && Growable(field))))
2725	{
2726	  if (!There_Is_Room && !Field_Grown(field, 1))
2727	    result = E_SYSTEM_ERROR;
2728	  else
2729	    {
2730	      winsch(form->w, (chtype)C_BLANK);
2731	      result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form);
2732	    }
2733	}
2734    }
2735  returnCode(result);
2736}
2737
2738/*---------------------------------------------------------------------------
2739|   Facility      :  libnform
2740|   Function      :  static int FE_Insert_Line(FORM * form)
2741|
2742|   Description   :  Insert a blank line at the cursor position
2743|
2744|   Return Values :  E_OK               - success
2745|                    E_REQUEST_DENIED   - line can not be inserted
2746+--------------------------------------------------------------------------*/
2747static int
2748FE_Insert_Line(FORM *form)
2749{
2750  FIELD *field = form->current;
2751  int result = E_REQUEST_DENIED;
2752
2753  T((T_CALLED("FE_Insert_Line(%p)"), (void *)form));
2754  if (Check_Char(form, field,
2755		 field->type, (int)C_BLANK, (TypeArgument *)(field->arg)))
2756    {
2757      bool Maybe_Done = (form->currow != (field->drows - 1)) &&
2758      Is_There_Room_For_A_Line(form);
2759
2760      if (!Single_Line_Field(field) &&
2761	  (Maybe_Done || Growable(field)))
2762	{
2763	  if (!Maybe_Done && !Field_Grown(field, 1))
2764	    result = E_SYSTEM_ERROR;
2765	  else
2766	    {
2767	      form->curcol = 0;
2768	      winsertln(form->w);
2769	      result = E_OK;
2770	    }
2771	}
2772    }
2773  returnCode(result);
2774}
2775
2776/*---------------------------------------------------------------------------
2777|   Facility      :  libnform
2778|   Function      :  static int FE_Delete_Character(FORM * form)
2779|
2780|   Description   :  Delete character at the cursor position
2781|
2782|   Return Values :  E_OK    - success
2783+--------------------------------------------------------------------------*/
2784static int
2785FE_Delete_Character(FORM *form)
2786{
2787  T((T_CALLED("FE_Delete_Character(%p)"), (void *)form));
2788  DeleteChar(form);
2789  returnCode(E_OK);
2790}
2791
2792/*---------------------------------------------------------------------------
2793|   Facility      :  libnform
2794|   Function      :  static int FE_Delete_Previous(FORM * form)
2795|
2796|   Description   :  Delete character before cursor. Again this is a rather
2797|                    difficult piece compared to others due to the overloading
2798|                    semantics of backspace.
2799|                    N.B.: The case of overloaded BS on first field position
2800|                          is already handled in the generic routine.
2801|
2802|   Return Values :  E_OK                - success
2803|                    E_REQUEST_DENIED    - Character can't be deleted
2804+--------------------------------------------------------------------------*/
2805static int
2806FE_Delete_Previous(FORM *form)
2807{
2808  FIELD *field = form->current;
2809
2810  T((T_CALLED("FE_Delete_Previous(%p)"), (void *)form));
2811  if (First_Position_In_Current_Field(form))
2812    returnCode(E_REQUEST_DENIED);
2813
2814  if ((--(form->curcol)) < 0)
2815    {
2816      FIELD_CELL *this_line, *prev_line, *prev_end, *this_end;
2817      int this_row = form->currow;
2818
2819      form->curcol++;
2820      if (form->status & _OVLMODE)
2821	returnCode(E_REQUEST_DENIED);
2822
2823      prev_line = Address_Of_Row_In_Buffer(field, (form->currow - 1));
2824      this_line = Address_Of_Row_In_Buffer(field, (form->currow));
2825      Synchronize_Buffer(form);
2826      prev_end = After_End_Of_Data(prev_line, field->dcols);
2827      this_end = After_End_Of_Data(this_line, field->dcols);
2828      if ((int)(this_end - this_line) >
2829	  (field->cols - (int)(prev_end - prev_line)))
2830	returnCode(E_REQUEST_DENIED);
2831      wmove(form->w, form->currow, form->curcol);
2832      wdeleteln(form->w);
2833      Adjust_Cursor_Position(form, prev_end);
2834      /*
2835       * If we did not really move to the previous line, help the user a
2836       * little.  It is however a little inconsistent.  Normally, when
2837       * backspacing around the point where text wraps to a new line in a
2838       * multi-line form, we absorb one keystroke for the wrapping point.  That
2839       * is consistent with SVr4 forms.  However, SVr4 does not allow typing
2840       * into the last column of the field, and requires the user to enter a
2841       * newline to move to the next line.  Therefore it can consistently eat
2842       * that keystroke.  Since ncurses allows the last column, it wraps
2843       * automatically (given the proper options).  But we cannot eat the
2844       * keystroke to back over the wrapping point, since that would put the
2845       * cursor past the end of the form field.  In this case, just delete the
2846       * character at the end of the field.
2847       */
2848      if (form->currow == this_row && this_row > 0)
2849	{
2850	  form->currow -= 1;
2851	  form->curcol = field->dcols - 1;
2852	  DeleteChar(form);
2853	}
2854      else
2855	{
2856	  wmove(form->w, form->currow, form->curcol);
2857	  myADDNSTR(form->w, this_line, (int)(this_end - this_line));
2858	}
2859    }
2860  else
2861    {
2862      DeleteChar(form);
2863    }
2864  returnCode(E_OK);
2865}
2866
2867/*---------------------------------------------------------------------------
2868|   Facility      :  libnform
2869|   Function      :  static int FE_Delete_Line(FORM * form)
2870|
2871|   Description   :  Delete line at cursor position.
2872|
2873|   Return Values :  E_OK  - success
2874+--------------------------------------------------------------------------*/
2875static int
2876FE_Delete_Line(FORM *form)
2877{
2878  T((T_CALLED("FE_Delete_Line(%p)"), (void *)form));
2879  form->curcol = 0;
2880  wdeleteln(form->w);
2881  returnCode(E_OK);
2882}
2883
2884/*---------------------------------------------------------------------------
2885|   Facility      :  libnform
2886|   Function      :  static int FE_Delete_Word(FORM * form)
2887|
2888|   Description   :  Delete word at cursor position
2889|
2890|   Return Values :  E_OK               - success
2891|                    E_REQUEST_DENIED   - failure
2892+--------------------------------------------------------------------------*/
2893static int
2894FE_Delete_Word(FORM *form)
2895{
2896  FIELD *field = form->current;
2897  FIELD_CELL *bp = Address_Of_Current_Row_In_Buffer(form);
2898  FIELD_CELL *ep = bp + field->dcols;
2899  FIELD_CELL *cp = bp + form->curcol;
2900  FIELD_CELL *s;
2901
2902  T((T_CALLED("FE_Delete_Word(%p)"), (void *)form));
2903  Synchronize_Buffer(form);
2904  if (ISBLANK(*cp))
2905    returnCode(E_REQUEST_DENIED);	/* not in word */
2906
2907  /* move cursor to begin of word and erase to end of screen-line */
2908  Adjust_Cursor_Position(form,
2909			 After_Last_Whitespace_Character(bp, form->curcol));
2910  wmove(form->w, form->currow, form->curcol);
2911  wclrtoeol(form->w);
2912
2913  /* skip over word in buffer */
2914  s = Get_First_Whitespace_Character(cp, (int)(ep - cp));
2915  /* to begin of next word    */
2916  s = Get_Start_Of_Data(s, (int)(ep - s));
2917  if ((s != cp) && !ISBLANK(*s))
2918    {
2919      /* copy remaining line to window */
2920      myADDNSTR(form->w, s, (int)(s - After_End_Of_Data(s, (int)(ep - s))));
2921    }
2922  returnCode(E_OK);
2923}
2924
2925/*---------------------------------------------------------------------------
2926|   Facility      :  libnform
2927|   Function      :  static int FE_Clear_To_End_Of_Line(FORM * form)
2928|
2929|   Description   :  Clear to end of current line.
2930|
2931|   Return Values :  E_OK   - success
2932+--------------------------------------------------------------------------*/
2933static int
2934FE_Clear_To_End_Of_Line(FORM *form)
2935{
2936  T((T_CALLED("FE_Clear_To_End_Of_Line(%p)"), (void *)form));
2937  wmove(form->w, form->currow, form->curcol);
2938  wclrtoeol(form->w);
2939  returnCode(E_OK);
2940}
2941
2942/*---------------------------------------------------------------------------
2943|   Facility      :  libnform
2944|   Function      :  static int FE_Clear_To_End_Of_Field(FORM * form)
2945|
2946|   Description   :  Clear to end of field.
2947|
2948|   Return Values :  E_OK   - success
2949+--------------------------------------------------------------------------*/
2950static int
2951FE_Clear_To_End_Of_Field(FORM *form)
2952{
2953  T((T_CALLED("FE_Clear_To_End_Of_Field(%p)"), (void *)form));
2954  wmove(form->w, form->currow, form->curcol);
2955  wclrtobot(form->w);
2956  returnCode(E_OK);
2957}
2958
2959/*---------------------------------------------------------------------------
2960|   Facility      :  libnform
2961|   Function      :  static int FE_Clear_Field(FORM * form)
2962|
2963|   Description   :  Clear entire field.
2964|
2965|   Return Values :  E_OK   - success
2966+--------------------------------------------------------------------------*/
2967static int
2968FE_Clear_Field(FORM *form)
2969{
2970  T((T_CALLED("FE_Clear_Field(%p)"), (void *)form));
2971  form->currow = form->curcol = 0;
2972  werase(form->w);
2973  returnCode(E_OK);
2974}
2975/*----------------------------------------------------------------------------
2976  END of Field Editing routines
2977  --------------------------------------------------------------------------*/
2978
2979/*----------------------------------------------------------------------------
2980  Edit Mode routines
2981  --------------------------------------------------------------------------*/
2982
2983/*---------------------------------------------------------------------------
2984|   Facility      :  libnform
2985|   Function      :  static int EM_Overlay_Mode(FORM * form)
2986|
2987|   Description   :  Switch to overlay mode.
2988|
2989|   Return Values :  E_OK   - success
2990+--------------------------------------------------------------------------*/
2991static int
2992EM_Overlay_Mode(FORM *form)
2993{
2994  T((T_CALLED("EM_Overlay_Mode(%p)"), (void *)form));
2995  SetStatus(form, _OVLMODE);
2996  returnCode(E_OK);
2997}
2998
2999/*---------------------------------------------------------------------------
3000|   Facility      :  libnform
3001|   Function      :  static int EM_Insert_Mode(FORM * form)
3002|
3003|   Description   :  Switch to insert mode
3004|
3005|   Return Values :  E_OK   - success
3006+--------------------------------------------------------------------------*/
3007static int
3008EM_Insert_Mode(FORM *form)
3009{
3010  T((T_CALLED("EM_Insert_Mode(%p)"), (void *)form));
3011  ClrStatus(form, _OVLMODE);
3012  returnCode(E_OK);
3013}
3014
3015/*----------------------------------------------------------------------------
3016  END of Edit Mode routines
3017  --------------------------------------------------------------------------*/
3018
3019/*----------------------------------------------------------------------------
3020  Helper routines for Choice Requests
3021  --------------------------------------------------------------------------*/
3022
3023/*---------------------------------------------------------------------------
3024|   Facility      :  libnform
3025|   Function      :  static bool Next_Choice(FORM * form,
3026|                                            FIELDTYPE * typ,
3027|                                            FIELD * field,
3028|                                            TypeArgument *argp)
3029|
3030|   Description   :  Get the next field choice. For linked types this is
3031|                    done recursively.
3032|
3033|   Return Values :  TRUE    - next choice successfully retrieved
3034|                    FALSE   - couldn't retrieve next choice
3035+--------------------------------------------------------------------------*/
3036static bool
3037Next_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3038{
3039  if (!typ || !(typ->status & _HAS_CHOICE))
3040    return FALSE;
3041
3042  if (typ->status & _LINKED_TYPE)
3043    {
3044      assert(argp);
3045      return (
3046	       Next_Choice(form, typ->left, field, argp->left) ||
3047	       Next_Choice(form, typ->right, field, argp->right));
3048    }
3049  else
3050    {
3051#if NCURSES_INTEROP_FUNCS
3052      assert(typ->enum_next.onext);
3053      if (typ->status & _GENERIC)
3054	return typ->enum_next.gnext(form, field, (void *)argp);
3055      else
3056	return typ->enum_next.onext(field, (void *)argp);
3057#else
3058      assert(typ->next);
3059      return typ->next(field, (void *)argp);
3060#endif
3061    }
3062}
3063
3064/*---------------------------------------------------------------------------
3065|   Facility      :  libnform
3066|   Function      :  static bool Previous_Choice(FORM * form,
3067|                                                FIELDTYPE * typ,
3068|                                                FIELD * field,
3069|                                                TypeArgument *argp)
3070|
3071|   Description   :  Get the previous field choice. For linked types this
3072|                    is done recursively.
3073|
3074|   Return Values :  TRUE    - previous choice successfully retrieved
3075|                    FALSE   - couldn't retrieve previous choice
3076+--------------------------------------------------------------------------*/
3077static bool
3078Previous_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3079{
3080  if (!typ || !(typ->status & _HAS_CHOICE))
3081    return FALSE;
3082
3083  if (typ->status & _LINKED_TYPE)
3084    {
3085      assert(argp);
3086      return (
3087	       Previous_Choice(form, typ->left, field, argp->left) ||
3088	       Previous_Choice(form, typ->right, field, argp->right));
3089    }
3090  else
3091    {
3092#if NCURSES_INTEROP_FUNCS
3093      assert(typ->enum_prev.oprev);
3094      if (typ->status & _GENERIC)
3095	return typ->enum_prev.gprev(form, field, (void *)argp);
3096      else
3097	return typ->enum_prev.oprev(field, (void *)argp);
3098#else
3099      assert(typ->prev);
3100      return typ->prev(field, (void *)argp);
3101#endif
3102    }
3103}
3104/*----------------------------------------------------------------------------
3105  End of Helper routines for Choice Requests
3106  --------------------------------------------------------------------------*/
3107
3108/*----------------------------------------------------------------------------
3109  Routines for Choice Requests
3110  --------------------------------------------------------------------------*/
3111
3112/*---------------------------------------------------------------------------
3113|   Facility      :  libnform
3114|   Function      :  static int CR_Next_Choice(FORM * form)
3115|
3116|   Description   :  Get the next field choice.
3117|
3118|   Return Values :  E_OK              - success
3119|                    E_REQUEST_DENIED  - next choice couldn't be retrieved
3120+--------------------------------------------------------------------------*/
3121static int
3122CR_Next_Choice(FORM *form)
3123{
3124  FIELD *field = form->current;
3125
3126  T((T_CALLED("CR_Next_Choice(%p)"), (void *)form));
3127  Synchronize_Buffer(form);
3128  returnCode((Next_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3129	     ? E_OK
3130	     : E_REQUEST_DENIED);
3131}
3132
3133/*---------------------------------------------------------------------------
3134|   Facility      :  libnform
3135|   Function      :  static int CR_Previous_Choice(FORM * form)
3136|
3137|   Description   :  Get the previous field choice.
3138|
3139|   Return Values :  E_OK              - success
3140|                    E_REQUEST_DENIED  - prev. choice couldn't be retrieved
3141+--------------------------------------------------------------------------*/
3142static int
3143CR_Previous_Choice(FORM *form)
3144{
3145  FIELD *field = form->current;
3146
3147  T((T_CALLED("CR_Previous_Choice(%p)"), (void *)form));
3148  Synchronize_Buffer(form);
3149  returnCode((Previous_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3150	     ? E_OK
3151	     : E_REQUEST_DENIED);
3152}
3153/*----------------------------------------------------------------------------
3154  End of Routines for Choice Requests
3155  --------------------------------------------------------------------------*/
3156
3157/*----------------------------------------------------------------------------
3158  Helper routines for Field Validations.
3159  --------------------------------------------------------------------------*/
3160
3161/*---------------------------------------------------------------------------
3162|   Facility      :  libnform
3163|   Function      :  static bool Check_Field(FORM* form,
3164|                                            FIELDTYPE * typ,
3165|                                            FIELD * field,
3166|                                            TypeArgument * argp)
3167|
3168|   Description   :  Check the field according to its fieldtype and its
3169|                    actual arguments. For linked fieldtypes this is done
3170|                    recursively.
3171|
3172|   Return Values :  TRUE       - field is valid
3173|                    FALSE      - field is invalid.
3174+--------------------------------------------------------------------------*/
3175static bool
3176Check_Field(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3177{
3178  if (typ)
3179    {
3180      if (Field_Has_Option(field, O_NULLOK))
3181	{
3182	  FIELD_CELL *bp = field->buf;
3183
3184	  assert(bp);
3185	  while (ISBLANK(*bp))
3186	    {
3187	      bp++;
3188	    }
3189	  if (CharOf(*bp) == 0)
3190	    return TRUE;
3191	}
3192
3193      if (typ->status & _LINKED_TYPE)
3194	{
3195	  assert(argp);
3196	  return (
3197		   Check_Field(form, typ->left, field, argp->left) ||
3198		   Check_Field(form, typ->right, field, argp->right));
3199	}
3200      else
3201	{
3202#if NCURSES_INTEROP_FUNCS
3203	  if (typ->fieldcheck.ofcheck)
3204	    {
3205	      if (typ->status & _GENERIC)
3206		return typ->fieldcheck.gfcheck(form, field, (void *)argp);
3207	      else
3208		return typ->fieldcheck.ofcheck(field, (void *)argp);
3209	    }
3210#else
3211	  if (typ->fcheck)
3212	    return typ->fcheck(field, (void *)argp);
3213#endif
3214	}
3215    }
3216  return TRUE;
3217}
3218
3219/*---------------------------------------------------------------------------
3220|   Facility      :  libnform
3221|   Function      :  bool _nc_Internal_Validation(FORM * form )
3222|
3223|   Description   :  Validate the current field of the form.
3224|
3225|   Return Values :  TRUE  - field is valid
3226|                    FALSE - field is invalid
3227+--------------------------------------------------------------------------*/
3228NCURSES_EXPORT(bool)
3229_nc_Internal_Validation(FORM *form)
3230{
3231  FIELD *field;
3232
3233  field = form->current;
3234
3235  Synchronize_Buffer(form);
3236  if ((form->status & _FCHECK_REQUIRED) ||
3237      (!(Field_Has_Option(field, O_PASSOK))))
3238    {
3239      if (!Check_Field(form, field->type, field, (TypeArgument *)(field->arg)))
3240	return FALSE;
3241      ClrStatus(form, _FCHECK_REQUIRED);
3242      SetStatus(field, _CHANGED);
3243      Synchronize_Linked_Fields(field);
3244    }
3245  return TRUE;
3246}
3247/*----------------------------------------------------------------------------
3248  End of Helper routines for Field Validations.
3249  --------------------------------------------------------------------------*/
3250
3251/*----------------------------------------------------------------------------
3252  Routines for Field Validation.
3253  --------------------------------------------------------------------------*/
3254
3255/*---------------------------------------------------------------------------
3256|   Facility      :  libnform
3257|   Function      :  static int FV_Validation(FORM * form)
3258|
3259|   Description   :  Validate the current field of the form.
3260|
3261|   Return Values :  E_OK             - field valid
3262|                    E_INVALID_FIELD  - field not valid
3263+--------------------------------------------------------------------------*/
3264static int
3265FV_Validation(FORM *form)
3266{
3267  T((T_CALLED("FV_Validation(%p)"), (void *)form));
3268  if (_nc_Internal_Validation(form))
3269    returnCode(E_OK);
3270  else
3271    returnCode(E_INVALID_FIELD);
3272}
3273/*----------------------------------------------------------------------------
3274  End of routines for Field Validation.
3275  --------------------------------------------------------------------------*/
3276
3277/*----------------------------------------------------------------------------
3278  Helper routines for Inter-Field Navigation
3279  --------------------------------------------------------------------------*/
3280
3281/*---------------------------------------------------------------------------
3282|   Facility      :  libnform
3283|   Function      :  static FIELD *Next_Field_On_Page(FIELD * field)
3284|
3285|   Description   :  Get the next field after the given field on the current
3286|                    page. The order of fields is the one defined by the
3287|                    fields array. Only visible and active fields are
3288|                    counted.
3289|
3290|   Return Values :  Pointer to the next field.
3291+--------------------------------------------------------------------------*/
3292NCURSES_INLINE static FIELD *
3293Next_Field_On_Page(FIELD *field)
3294{
3295  FORM *form = field->form;
3296  FIELD **field_on_page = &form->field[field->index];
3297  FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3298  FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3299
3300  do
3301    {
3302      field_on_page =
3303	(field_on_page == last_on_page) ? first_on_page : field_on_page + 1;
3304      if (Field_Is_Selectable(*field_on_page))
3305	break;
3306    }
3307  while (field != (*field_on_page));
3308  return (*field_on_page);
3309}
3310
3311/*---------------------------------------------------------------------------
3312|   Facility      :  libnform
3313|   Function      :  FIELD* _nc_First_Active_Field(FORM * form)
3314|
3315|   Description   :  Get the first active field on the current page,
3316|                    if there are such. If there are none, get the first
3317|                    visible field on the page. If there are also none,
3318|                    we return the first field on page and hope the best.
3319|
3320|   Return Values :  Pointer to calculated field.
3321+--------------------------------------------------------------------------*/
3322NCURSES_EXPORT(FIELD *)
3323_nc_First_Active_Field(FORM *form)
3324{
3325  FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3326  FIELD *proposed = Next_Field_On_Page(*last_on_page);
3327
3328  if (proposed == *last_on_page)
3329    {
3330      /* there might be the special situation, where there is no
3331         active and visible field on the current page. We then select
3332         the first visible field on this readonly page
3333       */
3334      if (Field_Is_Not_Selectable(proposed))
3335	{
3336	  FIELD **field = &form->field[proposed->index];
3337	  FIELD **first = &form->field[form->page[form->curpage].pmin];
3338
3339	  do
3340	    {
3341	      field = (field == last_on_page) ? first : field + 1;
3342	      if (Field_Has_Option(*field, O_VISIBLE))
3343		break;
3344	    }
3345	  while (proposed != (*field));
3346
3347	  proposed = *field;
3348
3349	  if ((proposed == *last_on_page) &&
3350	      !((unsigned)proposed->opts & O_VISIBLE))
3351	    {
3352	      /* This means, there is also no visible field on the page.
3353	         So we propose the first one and hope the very best...
3354	         Some very clever user has designed a readonly and invisible
3355	         page on this form.
3356	       */
3357	      proposed = *first;
3358	    }
3359	}
3360    }
3361  return (proposed);
3362}
3363
3364/*---------------------------------------------------------------------------
3365|   Facility      :  libnform
3366|   Function      :  static FIELD *Previous_Field_On_Page(FIELD * field)
3367|
3368|   Description   :  Get the previous field before the given field on the
3369|                    current page. The order of fields is the one defined by
3370|                    the fields array. Only visible and active fields are
3371|                    counted.
3372|
3373|   Return Values :  Pointer to the previous field.
3374+--------------------------------------------------------------------------*/
3375NCURSES_INLINE static FIELD *
3376Previous_Field_On_Page(FIELD *field)
3377{
3378  FORM *form = field->form;
3379  FIELD **field_on_page = &form->field[field->index];
3380  FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3381  FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3382
3383  do
3384    {
3385      field_on_page =
3386	(field_on_page == first_on_page) ? last_on_page : field_on_page - 1;
3387      if (Field_Is_Selectable(*field_on_page))
3388	break;
3389    }
3390  while (field != (*field_on_page));
3391
3392  return (*field_on_page);
3393}
3394
3395/*---------------------------------------------------------------------------
3396|   Facility      :  libnform
3397|   Function      :  static FIELD *Sorted_Next_Field(FIELD * field)
3398|
3399|   Description   :  Get the next field after the given field on the current
3400|                    page. The order of fields is the one defined by the
3401|                    (row,column) geometry, rows are major.
3402|
3403|   Return Values :  Pointer to the next field.
3404+--------------------------------------------------------------------------*/
3405NCURSES_INLINE static FIELD *
3406Sorted_Next_Field(FIELD *field)
3407{
3408  FIELD *field_on_page = field;
3409
3410  do
3411    {
3412      field_on_page = field_on_page->snext;
3413      if (Field_Is_Selectable(field_on_page))
3414	break;
3415    }
3416  while (field_on_page != field);
3417
3418  return (field_on_page);
3419}
3420
3421/*---------------------------------------------------------------------------
3422|   Facility      :  libnform
3423|   Function      :  static FIELD *Sorted_Previous_Field(FIELD * field)
3424|
3425|   Description   :  Get the previous field before the given field on the
3426|                    current page. The order of fields is the one defined
3427|                    by the (row,column) geometry, rows are major.
3428|
3429|   Return Values :  Pointer to the previous field.
3430+--------------------------------------------------------------------------*/
3431NCURSES_INLINE static FIELD *
3432Sorted_Previous_Field(FIELD *field)
3433{
3434  FIELD *field_on_page = field;
3435
3436  do
3437    {
3438      field_on_page = field_on_page->sprev;
3439      if (Field_Is_Selectable(field_on_page))
3440	break;
3441    }
3442  while (field_on_page != field);
3443
3444  return (field_on_page);
3445}
3446
3447/*---------------------------------------------------------------------------
3448|   Facility      :  libnform
3449|   Function      :  static FIELD *Left_Neighbor_Field(FIELD * field)
3450|
3451|   Description   :  Get the left neighbor of the field on the same line
3452|                    and the same page. Cycles through the line.
3453|
3454|   Return Values :  Pointer to left neighbor field.
3455+--------------------------------------------------------------------------*/
3456NCURSES_INLINE static FIELD *
3457Left_Neighbor_Field(FIELD *field)
3458{
3459  FIELD *field_on_page = field;
3460
3461  /* For a field that has really a left neighbor, the while clause
3462     immediately fails and the loop is left, positioned at the right
3463     neighbor. Otherwise we cycle backwards through the sorted field list
3464     until we enter the same line (from the right end).
3465   */
3466  do
3467    {
3468      field_on_page = Sorted_Previous_Field(field_on_page);
3469    }
3470  while (field_on_page->frow != field->frow);
3471
3472  return (field_on_page);
3473}
3474
3475/*---------------------------------------------------------------------------
3476|   Facility      :  libnform
3477|   Function      :  static FIELD *Right_Neighbor_Field(FIELD * field)
3478|
3479|   Description   :  Get the right neighbor of the field on the same line
3480|                    and the same page.
3481|
3482|   Return Values :  Pointer to right neighbor field.
3483+--------------------------------------------------------------------------*/
3484NCURSES_INLINE static FIELD *
3485Right_Neighbor_Field(FIELD *field)
3486{
3487  FIELD *field_on_page = field;
3488
3489  /* See the comments on Left_Neighbor_Field to understand how it works */
3490  do
3491    {
3492      field_on_page = Sorted_Next_Field(field_on_page);
3493    }
3494  while (field_on_page->frow != field->frow);
3495
3496  return (field_on_page);
3497}
3498
3499/*---------------------------------------------------------------------------
3500|   Facility      :  libnform
3501|   Function      :  static FIELD *Upper_Neighbor_Field(FIELD * field)
3502|
3503|   Description   :  Because of the row-major nature of sorting the fields,
3504|                    it is more difficult to define whats the upper neighbor
3505|                    field really means. We define that it must be on a
3506|                    'previous' line (cyclic order!) and is the rightmost
3507|                    field laying on the left side of the given field. If
3508|                    this set is empty, we take the first field on the line.
3509|
3510|   Return Values :  Pointer to the upper neighbor field.
3511+--------------------------------------------------------------------------*/
3512static FIELD *
3513Upper_Neighbor_Field(FIELD *field)
3514{
3515  FIELD *field_on_page = field;
3516  int frow = field->frow;
3517  int fcol = field->fcol;
3518
3519  /* Walk back to the 'previous' line. The second term in the while clause
3520     just guarantees that we stop if we cycled through the line because
3521     there might be no 'previous' line if the page has just one line.
3522   */
3523  do
3524    {
3525      field_on_page = Sorted_Previous_Field(field_on_page);
3526    }
3527  while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3528
3529  if (field_on_page->frow != frow)
3530    {
3531      /* We really found a 'previous' line. We are positioned at the
3532         rightmost field on this line */
3533      frow = field_on_page->frow;
3534
3535      /* We walk to the left as long as we are really right of the
3536         field. */
3537      while (field_on_page->frow == frow && field_on_page->fcol > fcol)
3538	field_on_page = Sorted_Previous_Field(field_on_page);
3539
3540      /* If we wrapped, just go to the right which is the first field on
3541         the row */
3542      if (field_on_page->frow != frow)
3543	field_on_page = Sorted_Next_Field(field_on_page);
3544    }
3545
3546  return (field_on_page);
3547}
3548
3549/*---------------------------------------------------------------------------
3550|   Facility      :  libnform
3551|   Function      :  static FIELD *Down_Neighbor_Field(FIELD * field)
3552|
3553|   Description   :  Because of the row-major nature of sorting the fields,
3554|                    its more difficult to define whats the down neighbor
3555|                    field really means. We define that it must be on a
3556|                    'next' line (cyclic order!) and is the leftmost
3557|                    field laying on the right side of the given field. If
3558|                    this set is empty, we take the last field on the line.
3559|
3560|   Return Values :  Pointer to the upper neighbor field.
3561+--------------------------------------------------------------------------*/
3562static FIELD *
3563Down_Neighbor_Field(FIELD *field)
3564{
3565  FIELD *field_on_page = field;
3566  int frow = field->frow;
3567  int fcol = field->fcol;
3568
3569  /* Walk forward to the 'next' line. The second term in the while clause
3570     just guarantees that we stop if we cycled through the line because
3571     there might be no 'next' line if the page has just one line.
3572   */
3573  do
3574    {
3575      field_on_page = Sorted_Next_Field(field_on_page);
3576    }
3577  while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3578
3579  if (field_on_page->frow != frow)
3580    {
3581      /* We really found a 'next' line. We are positioned at the rightmost
3582         field on this line */
3583      frow = field_on_page->frow;
3584
3585      /* We walk to the right as long as we are really left of the
3586         field. */
3587      while (field_on_page->frow == frow && field_on_page->fcol < fcol)
3588	field_on_page = Sorted_Next_Field(field_on_page);
3589
3590      /* If we wrapped, just go to the left which is the last field on
3591         the row */
3592      if (field_on_page->frow != frow)
3593	field_on_page = Sorted_Previous_Field(field_on_page);
3594    }
3595
3596  return (field_on_page);
3597}
3598
3599/*----------------------------------------------------------------------------
3600  Inter-Field Navigation routines
3601  --------------------------------------------------------------------------*/
3602
3603/*---------------------------------------------------------------------------
3604|   Facility      :  libnform
3605|   Function      :  static int Inter_Field_Navigation(
3606|                                           int (* const fct) (FORM *),
3607|                                           FORM * form)
3608|
3609|   Description   :  Generic behavior for changing the current field, the
3610|                    field is left and a new field is entered. So the field
3611|                    must be validated and the field init/term hooks must
3612|                    be called.
3613|
3614|   Return Values :  E_OK                - success
3615|                    E_INVALID_FIELD     - field is invalid
3616|                    some other          - error from subordinate call
3617+--------------------------------------------------------------------------*/
3618static int
3619Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form)
3620{
3621  int res;
3622
3623  if (!_nc_Internal_Validation(form))
3624    res = E_INVALID_FIELD;
3625  else
3626    {
3627      Call_Hook(form, fieldterm);
3628      res = fct(form);
3629      Call_Hook(form, fieldinit);
3630    }
3631  return res;
3632}
3633
3634/*---------------------------------------------------------------------------
3635|   Facility      :  libnform
3636|   Function      :  static int FN_Next_Field(FORM * form)
3637|
3638|   Description   :  Move to the next field on the current page of the form
3639|
3640|   Return Values :  E_OK                 - success
3641|                    != E_OK              - error from subordinate call
3642+--------------------------------------------------------------------------*/
3643static int
3644FN_Next_Field(FORM *form)
3645{
3646  T((T_CALLED("FN_Next_Field(%p)"), (void *)form));
3647  returnCode(_nc_Set_Current_Field(form,
3648				   Next_Field_On_Page(form->current)));
3649}
3650
3651/*---------------------------------------------------------------------------
3652|   Facility      :  libnform
3653|   Function      :  static int FN_Previous_Field(FORM * form)
3654|
3655|   Description   :  Move to the previous field on the current page of the
3656|                    form
3657|
3658|   Return Values :  E_OK                 - success
3659|                    != E_OK              - error from subordinate call
3660+--------------------------------------------------------------------------*/
3661static int
3662FN_Previous_Field(FORM *form)
3663{
3664  T((T_CALLED("FN_Previous_Field(%p)"), (void *)form));
3665  returnCode(_nc_Set_Current_Field(form,
3666				   Previous_Field_On_Page(form->current)));
3667}
3668
3669/*---------------------------------------------------------------------------
3670|   Facility      :  libnform
3671|   Function      :  static int FN_First_Field(FORM * form)
3672|
3673|   Description   :  Move to the first field on the current page of the form
3674|
3675|   Return Values :  E_OK                 - success
3676|                    != E_OK              - error from subordinate call
3677+--------------------------------------------------------------------------*/
3678static int
3679FN_First_Field(FORM *form)
3680{
3681  T((T_CALLED("FN_First_Field(%p)"), (void *)form));
3682  returnCode(_nc_Set_Current_Field(form,
3683				   Next_Field_On_Page(form->field[form->page[form->curpage].pmax])));
3684}
3685
3686/*---------------------------------------------------------------------------
3687|   Facility      :  libnform
3688|   Function      :  static int FN_Last_Field(FORM * form)
3689|
3690|   Description   :  Move to the last field on the current page of the form
3691|
3692|   Return Values :  E_OK                 - success
3693|                    != E_OK              - error from subordinate call
3694+--------------------------------------------------------------------------*/
3695static int
3696FN_Last_Field(FORM *form)
3697{
3698  T((T_CALLED("FN_Last_Field(%p)"), (void *)form));
3699  returnCode(
3700	      _nc_Set_Current_Field(form,
3701				    Previous_Field_On_Page(form->field[form->page[form->curpage].pmin])));
3702}
3703
3704/*---------------------------------------------------------------------------
3705|   Facility      :  libnform
3706|   Function      :  static int FN_Sorted_Next_Field(FORM * form)
3707|
3708|   Description   :  Move to the sorted next field on the current page
3709|                    of the form.
3710|
3711|   Return Values :  E_OK            - success
3712|                    != E_OK         - error from subordinate call
3713+--------------------------------------------------------------------------*/
3714static int
3715FN_Sorted_Next_Field(FORM *form)
3716{
3717  T((T_CALLED("FN_Sorted_Next_Field(%p)"), (void *)form));
3718  returnCode(_nc_Set_Current_Field(form,
3719				   Sorted_Next_Field(form->current)));
3720}
3721
3722/*---------------------------------------------------------------------------
3723|   Facility      :  libnform
3724|   Function      :  static int FN_Sorted_Previous_Field(FORM * form)
3725|
3726|   Description   :  Move to the sorted previous field on the current page
3727|                    of the form.
3728|
3729|   Return Values :  E_OK            - success
3730|                    != E_OK         - error from subordinate call
3731+--------------------------------------------------------------------------*/
3732static int
3733FN_Sorted_Previous_Field(FORM *form)
3734{
3735  T((T_CALLED("FN_Sorted_Previous_Field(%p)"), (void *)form));
3736  returnCode(_nc_Set_Current_Field(form,
3737				   Sorted_Previous_Field(form->current)));
3738}
3739
3740/*---------------------------------------------------------------------------
3741|   Facility      :  libnform
3742|   Function      :  static int FN_Sorted_First_Field(FORM * form)
3743|
3744|   Description   :  Move to the sorted first field on the current page
3745|                    of the form.
3746|
3747|   Return Values :  E_OK            - success
3748|                    != E_OK         - error from subordinate call
3749+--------------------------------------------------------------------------*/
3750static int
3751FN_Sorted_First_Field(FORM *form)
3752{
3753  T((T_CALLED("FN_Sorted_First_Field(%p)"), (void *)form));
3754  returnCode(_nc_Set_Current_Field(form,
3755				   Sorted_Next_Field(form->field[form->page[form->curpage].smax])));
3756}
3757
3758/*---------------------------------------------------------------------------
3759|   Facility      :  libnform
3760|   Function      :  static int FN_Sorted_Last_Field(FORM * form)
3761|
3762|   Description   :  Move to the sorted last field on the current page
3763|                    of the form.
3764|
3765|   Return Values :  E_OK            - success
3766|                    != E_OK         - error from subordinate call
3767+--------------------------------------------------------------------------*/
3768static int
3769FN_Sorted_Last_Field(FORM *form)
3770{
3771  T((T_CALLED("FN_Sorted_Last_Field(%p)"), (void *)form));
3772  returnCode(_nc_Set_Current_Field(form,
3773				   Sorted_Previous_Field(form->field[form->page[form->curpage].smin])));
3774}
3775
3776/*---------------------------------------------------------------------------
3777|   Facility      :  libnform
3778|   Function      :  static int FN_Left_Field(FORM * form)
3779|
3780|   Description   :  Get the field on the left of the current field on the
3781|                    same line and the same page. Cycles through the line.
3782|
3783|   Return Values :  E_OK            - success
3784|                    != E_OK         - error from subordinate call
3785+--------------------------------------------------------------------------*/
3786static int
3787FN_Left_Field(FORM *form)
3788{
3789  T((T_CALLED("FN_Left_Field(%p)"), (void *)form));
3790  returnCode(_nc_Set_Current_Field(form,
3791				   Left_Neighbor_Field(form->current)));
3792}
3793
3794/*---------------------------------------------------------------------------
3795|   Facility      :  libnform
3796|   Function      :  static int FN_Right_Field(FORM * form)
3797|
3798|   Description   :  Get the field on the right of the current field on the
3799|                    same line and the same page. Cycles through the line.
3800|
3801|   Return Values :  E_OK            - success
3802|                    != E_OK         - error from subordinate call
3803+--------------------------------------------------------------------------*/
3804static int
3805FN_Right_Field(FORM *form)
3806{
3807  T((T_CALLED("FN_Right_Field(%p)"), (void *)form));
3808  returnCode(_nc_Set_Current_Field(form,
3809				   Right_Neighbor_Field(form->current)));
3810}
3811
3812/*---------------------------------------------------------------------------
3813|   Facility      :  libnform
3814|   Function      :  static int FN_Up_Field(FORM * form)
3815|
3816|   Description   :  Get the upper neighbor of the current field. This
3817|                    cycles through the page. See the comments of the
3818|                    Upper_Neighbor_Field function to understand how
3819|                    'upper' is defined.
3820|
3821|   Return Values :  E_OK            - success
3822|                    != E_OK         - error from subordinate call
3823+--------------------------------------------------------------------------*/
3824static int
3825FN_Up_Field(FORM *form)
3826{
3827  T((T_CALLED("FN_Up_Field(%p)"), (void *)form));
3828  returnCode(_nc_Set_Current_Field(form,
3829				   Upper_Neighbor_Field(form->current)));
3830}
3831
3832/*---------------------------------------------------------------------------
3833|   Facility      :  libnform
3834|   Function      :  static int FN_Down_Field(FORM * form)
3835|
3836|   Description   :  Get the down neighbor of the current field. This
3837|                    cycles through the page. See the comments of the
3838|                    Down_Neighbor_Field function to understand how
3839|                    'down' is defined.
3840|
3841|   Return Values :  E_OK            - success
3842|                    != E_OK         - error from subordinate call
3843+--------------------------------------------------------------------------*/
3844static int
3845FN_Down_Field(FORM *form)
3846{
3847  T((T_CALLED("FN_Down_Field(%p)"), (void *)form));
3848  returnCode(_nc_Set_Current_Field(form,
3849				   Down_Neighbor_Field(form->current)));
3850}
3851/*----------------------------------------------------------------------------
3852  END of Field Navigation routines
3853  --------------------------------------------------------------------------*/
3854
3855/*----------------------------------------------------------------------------
3856  Helper routines for Page Navigation
3857  --------------------------------------------------------------------------*/
3858
3859/*---------------------------------------------------------------------------
3860|   Facility      :  libnform
3861|   Function      :  int _nc_Set_Form_Page(FORM * form,
3862|                                          int page,
3863|                                          FIELD * field)
3864|
3865|   Description   :  Make the given page number the current page and make
3866|                    the given field the current field on the page. If
3867|                    for the field NULL is given, make the first field on
3868|                    the page the current field. The routine acts only
3869|                    if the requested page is not the current page.
3870|
3871|   Return Values :  E_OK                - success
3872|                    != E_OK             - error from subordinate call
3873|                    E_BAD_ARGUMENT      - invalid field pointer
3874|                    E_SYSTEM_ERROR      - some severe basic error
3875+--------------------------------------------------------------------------*/
3876NCURSES_EXPORT(int)
3877_nc_Set_Form_Page(FORM *form, int page, FIELD *field)
3878{
3879  int res = E_OK;
3880
3881  if ((form->curpage != page))
3882    {
3883      FIELD *last_field, *field_on_page;
3884
3885      werase(Get_Form_Window(form));
3886      form->curpage = (short)page;
3887      last_field = field_on_page = form->field[form->page[page].smin];
3888      do
3889	{
3890	  if ((unsigned)field_on_page->opts & O_VISIBLE)
3891	    if ((res = Display_Field(field_on_page)) != E_OK)
3892	      return (res);
3893	  field_on_page = field_on_page->snext;
3894	}
3895      while (field_on_page != last_field);
3896
3897      if (field)
3898	res = _nc_Set_Current_Field(form, field);
3899      else
3900	/* N.B.: we don't encapsulate this by Inter_Field_Navigation(),
3901	   because this is already executed in a page navigation
3902	   context that contains field navigation
3903	 */
3904	res = FN_First_Field(form);
3905    }
3906  return (res);
3907}
3908
3909/*---------------------------------------------------------------------------
3910|   Facility      :  libnform
3911|   Function      :  static int Next_Page_Number(const FORM * form)
3912|
3913|   Description   :  Calculate the page number following the current page
3914|                    number. This cycles if the highest page number is
3915|                    reached.
3916|
3917|   Return Values :  The next page number
3918+--------------------------------------------------------------------------*/
3919NCURSES_INLINE static int
3920Next_Page_Number(const FORM *form)
3921{
3922  return (form->curpage + 1) % form->maxpage;
3923}
3924
3925/*---------------------------------------------------------------------------
3926|   Facility      :  libnform
3927|   Function      :  static int Previous_Page_Number(const FORM * form)
3928|
3929|   Description   :  Calculate the page number before the current page
3930|                    number. This cycles if the first page number is
3931|                    reached.
3932|
3933|   Return Values :  The previous page number
3934+--------------------------------------------------------------------------*/
3935NCURSES_INLINE static int
3936Previous_Page_Number(const FORM *form)
3937{
3938  return (form->curpage != 0 ? form->curpage - 1 : form->maxpage - 1);
3939}
3940
3941/*----------------------------------------------------------------------------
3942  Page Navigation routines
3943  --------------------------------------------------------------------------*/
3944
3945/*---------------------------------------------------------------------------
3946|   Facility      :  libnform
3947|   Function      :  static int Page_Navigation(
3948|                                               int (* const fct) (FORM *),
3949|                                               FORM * form)
3950|
3951|   Description   :  Generic behavior for changing a page. This means
3952|                    that the field is left and a new field is entered.
3953|                    So the field must be validated and the field init/term
3954|                    hooks must be called. Because also the page is changed,
3955|                    the forms init/term hooks must be called also.
3956|
3957|   Return Values :  E_OK                - success
3958|                    E_INVALID_FIELD     - field is invalid
3959|                    some other          - error from subordinate call
3960+--------------------------------------------------------------------------*/
3961static int
3962Page_Navigation(int (*const fct) (FORM *), FORM *form)
3963{
3964  int res;
3965
3966  if (!_nc_Internal_Validation(form))
3967    res = E_INVALID_FIELD;
3968  else
3969    {
3970      Call_Hook(form, fieldterm);
3971      Call_Hook(form, formterm);
3972      res = fct(form);
3973      Call_Hook(form, forminit);
3974      Call_Hook(form, fieldinit);
3975    }
3976  return res;
3977}
3978
3979/*---------------------------------------------------------------------------
3980|   Facility      :  libnform
3981|   Function      :  static int PN_Next_Page(FORM * form)
3982|
3983|   Description   :  Move to the next page of the form
3984|
3985|   Return Values :  E_OK                - success
3986|                    != E_OK             - error from subordinate call
3987+--------------------------------------------------------------------------*/
3988static int
3989PN_Next_Page(FORM *form)
3990{
3991  T((T_CALLED("PN_Next_Page(%p)"), (void *)form));
3992  returnCode(_nc_Set_Form_Page(form, Next_Page_Number(form), (FIELD *)0));
3993}
3994
3995/*---------------------------------------------------------------------------
3996|   Facility      :  libnform
3997|   Function      :  static int PN_Previous_Page(FORM * form)
3998|
3999|   Description   :  Move to the previous page of the form
4000|
4001|   Return Values :  E_OK              - success
4002|                    != E_OK           - error from subordinate call
4003+--------------------------------------------------------------------------*/
4004static int
4005PN_Previous_Page(FORM *form)
4006{
4007  T((T_CALLED("PN_Previous_Page(%p)"), (void *)form));
4008  returnCode(_nc_Set_Form_Page(form, Previous_Page_Number(form), (FIELD *)0));
4009}
4010
4011/*---------------------------------------------------------------------------
4012|   Facility      :  libnform
4013|   Function      :  static int PN_First_Page(FORM * form)
4014|
4015|   Description   :  Move to the first page of the form
4016|
4017|   Return Values :  E_OK              - success
4018|                    != E_OK           - error from subordinate call
4019+--------------------------------------------------------------------------*/
4020static int
4021PN_First_Page(FORM *form)
4022{
4023  T((T_CALLED("PN_First_Page(%p)"), (void *)form));
4024  returnCode(_nc_Set_Form_Page(form, 0, (FIELD *)0));
4025}
4026
4027/*---------------------------------------------------------------------------
4028|   Facility      :  libnform
4029|   Function      :  static int PN_Last_Page(FORM * form)
4030|
4031|   Description   :  Move to the last page of the form
4032|
4033|   Return Values :  E_OK              - success
4034|                    != E_OK           - error from subordinate call
4035+--------------------------------------------------------------------------*/
4036static int
4037PN_Last_Page(FORM *form)
4038{
4039  T((T_CALLED("PN_Last_Page(%p)"), (void *)form));
4040  returnCode(_nc_Set_Form_Page(form, form->maxpage - 1, (FIELD *)0));
4041}
4042
4043/*----------------------------------------------------------------------------
4044  END of Field Navigation routines
4045  --------------------------------------------------------------------------*/
4046
4047/*----------------------------------------------------------------------------
4048  Helper routines for the core form driver.
4049  --------------------------------------------------------------------------*/
4050
4051# if USE_WIDEC_SUPPORT
4052/*---------------------------------------------------------------------------
4053|   Facility      :  libnform
4054|   Function      :  static int Data_Entry_w(FORM * form, wchar_t c)
4055|
4056|   Description   :  Enter the wide character c into at the current
4057|                    position of the current field of the form.
4058|
4059|   Return Values :  E_OK              - success
4060|                    E_REQUEST_DENIED  - driver could not process the request
4061|                    E_SYSTEM_ERROR    -
4062+--------------------------------------------------------------------------*/
4063static int
4064Data_Entry_w(FORM *form, wchar_t c)
4065{
4066  FIELD *field = form->current;
4067  int result = E_REQUEST_DENIED;
4068
4069  T((T_CALLED("Data_Entry(%p,%s)"), (void *)form, _tracechtype((chtype)c)));
4070  if ((Field_Has_Option(field, O_EDIT))
4071#if FIX_FORM_INACTIVE_BUG
4072      && (Field_Has_Option(field, O_ACTIVE))
4073#endif
4074    )
4075    {
4076      wchar_t given[2];
4077      cchar_t temp_ch;
4078
4079      given[0] = c;
4080      given[1] = 0;
4081      setcchar(&temp_ch, given, 0, 0, (void *)0);
4082      if ((Field_Has_Option(field, O_BLANK)) &&
4083	  First_Position_In_Current_Field(form) &&
4084	  !(form->status & _FCHECK_REQUIRED) &&
4085	  !(form->status & _WINDOW_MODIFIED))
4086	werase(form->w);
4087
4088      if (form->status & _OVLMODE)
4089	{
4090	  wadd_wch(form->w, &temp_ch);
4091	}
4092      else
4093	/* no _OVLMODE */
4094	{
4095	  bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
4096
4097	  if (!(There_Is_Room ||
4098		((Single_Line_Field(field) && Growable(field)))))
4099	    RETURN(E_REQUEST_DENIED);
4100
4101	  if (!There_Is_Room && !Field_Grown(field, 1))
4102	    RETURN(E_SYSTEM_ERROR);
4103
4104	  wins_wch(form->w, &temp_ch);
4105	}
4106
4107      if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
4108	{
4109	  bool End_Of_Field = (((field->drows - 1) == form->currow) &&
4110			       ((field->dcols - 1) == form->curcol));
4111
4112	  form->status |= _WINDOW_MODIFIED;
4113	  if (End_Of_Field && !Growable(field) && (Field_Has_Option(field, O_AUTOSKIP)))
4114	    result = Inter_Field_Navigation(FN_Next_Field, form);
4115	  else
4116	    {
4117	      if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
4118		result = E_SYSTEM_ERROR;
4119	      else
4120		{
4121		  /*
4122		   * We have just added a byte to the form field.  It may have
4123		   * been part of a multibyte character.  If it was, the
4124		   * addch_used field is nonzero and we should not try to move
4125		   * to a new column.
4126		   */
4127		  if (WINDOW_EXT(form->w, addch_used) == 0)
4128		    IFN_Next_Character(form);
4129
4130		  result = E_OK;
4131		}
4132	    }
4133	}
4134    }
4135  RETURN(result);
4136}
4137# endif
4138
4139/*---------------------------------------------------------------------------
4140|   Facility      :  libnform
4141|   Function      :  static int Data_Entry(FORM * form,int c)
4142|
4143|   Description   :  Enter character c into at the current position of the
4144|                    current field of the form.
4145|
4146|   Return Values :  E_OK              - success
4147|                    E_REQUEST_DENIED  - driver could not process the request
4148|                    E_SYSTEM_ERROR    -
4149+--------------------------------------------------------------------------*/
4150static int
4151Data_Entry(FORM *form, int c)
4152{
4153  FIELD *field = form->current;
4154  int result = E_REQUEST_DENIED;
4155
4156  T((T_CALLED("Data_Entry(%p,%s)"), (void *)form, _tracechtype((chtype)c)));
4157  if ((Field_Has_Option(field, O_EDIT))
4158#if FIX_FORM_INACTIVE_BUG
4159      && (Field_Has_Option(field, O_ACTIVE))
4160#endif
4161    )
4162    {
4163      if ((Field_Has_Option(field, O_BLANK)) &&
4164	  First_Position_In_Current_Field(form) &&
4165	  !(form->status & _FCHECK_REQUIRED) &&
4166	  !(form->status & _WINDOW_MODIFIED))
4167	werase(form->w);
4168
4169      if (form->status & _OVLMODE)
4170	{
4171	  waddch(form->w, (chtype)c);
4172	}
4173      else
4174	/* no _OVLMODE */
4175	{
4176	  bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
4177
4178	  if (!(There_Is_Room ||
4179		((Single_Line_Field(field) && Growable(field)))))
4180	    RETURN(E_REQUEST_DENIED);
4181
4182	  if (!There_Is_Room && !Field_Grown(field, 1))
4183	    RETURN(E_SYSTEM_ERROR);
4184
4185	  winsch(form->w, (chtype)c);
4186	}
4187
4188      if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
4189	{
4190	  bool End_Of_Field = (((field->drows - 1) == form->currow) &&
4191			       ((field->dcols - 1) == form->curcol));
4192
4193	  if (Field_Has_Option(field, O_EDGE_INSERT_STAY))
4194	    move_after_insert = !!(form->curcol
4195				   - form->begincol
4196				   - field->cols
4197				   + 1);
4198
4199	  SetStatus(form, _WINDOW_MODIFIED);
4200	  if (End_Of_Field && !Growable(field) && (Field_Has_Option(field, O_AUTOSKIP)))
4201	    result = Inter_Field_Navigation(FN_Next_Field, form);
4202	  else
4203	    {
4204	      if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
4205		result = E_SYSTEM_ERROR;
4206	      else
4207		{
4208#if USE_WIDEC_SUPPORT
4209		  /*
4210		   * We have just added a byte to the form field.  It may have
4211		   * been part of a multibyte character.  If it was, the
4212		   * addch_used field is nonzero and we should not try to move
4213		   * to a new column.
4214		   */
4215		  if (WINDOW_EXT(form->w, addch_used) == 0)
4216		    IFN_Next_Character(form);
4217#else
4218		  IFN_Next_Character(form);
4219#endif
4220		  result = E_OK;
4221		}
4222	    }
4223	}
4224    }
4225  RETURN(result);
4226}
4227
4228/* Structure to describe the binding of a request code to a function.
4229   The member keycode codes the request value as well as the generic
4230   routine to use for the request. The code for the generic routine
4231   is coded in the upper 16 Bits while the request code is coded in
4232   the lower 16 bits.
4233
4234   In terms of C++ you might think of a request as a class with a
4235   virtual method "perform". The different types of request are
4236   derived from this base class and overload (or not) the base class
4237   implementation of perform.
4238*/
4239typedef struct
4240{
4241  int keycode;			/* must be at least 32 bit: hi:mode, lo: key */
4242  int (*cmd) (FORM *);		/* low level driver routine for this key     */
4243}
4244Binding_Info;
4245
4246/* You may see this is the class-id of the request type class */
4247#define ID_PN    (0x00000000)	/* Page navigation           */
4248#define ID_FN    (0x00010000)	/* Inter-Field navigation    */
4249#define ID_IFN   (0x00020000)	/* Intra-Field navigation    */
4250#define ID_VSC   (0x00030000)	/* Vertical Scrolling        */
4251#define ID_HSC   (0x00040000)	/* Horizontal Scrolling      */
4252#define ID_FE    (0x00050000)	/* Field Editing             */
4253#define ID_EM    (0x00060000)	/* Edit Mode                 */
4254#define ID_FV    (0x00070000)	/* Field Validation          */
4255#define ID_CH    (0x00080000)	/* Choice                    */
4256#define ID_Mask  (0xffff0000)
4257#define Key_Mask (0x0000ffff)
4258#define ID_Shft  (16)
4259
4260/* This array holds all the Binding Infos */
4261/* *INDENT-OFF* */
4262static const Binding_Info bindings[MAX_FORM_COMMAND - MIN_FORM_COMMAND + 1] =
4263{
4264  { REQ_NEXT_PAGE    |ID_PN  ,PN_Next_Page},
4265  { REQ_PREV_PAGE    |ID_PN  ,PN_Previous_Page},
4266  { REQ_FIRST_PAGE   |ID_PN  ,PN_First_Page},
4267  { REQ_LAST_PAGE    |ID_PN  ,PN_Last_Page},
4268
4269  { REQ_NEXT_FIELD   |ID_FN  ,FN_Next_Field},
4270  { REQ_PREV_FIELD   |ID_FN  ,FN_Previous_Field},
4271  { REQ_FIRST_FIELD  |ID_FN  ,FN_First_Field},
4272  { REQ_LAST_FIELD   |ID_FN  ,FN_Last_Field},
4273  { REQ_SNEXT_FIELD  |ID_FN  ,FN_Sorted_Next_Field},
4274  { REQ_SPREV_FIELD  |ID_FN  ,FN_Sorted_Previous_Field},
4275  { REQ_SFIRST_FIELD |ID_FN  ,FN_Sorted_First_Field},
4276  { REQ_SLAST_FIELD  |ID_FN  ,FN_Sorted_Last_Field},
4277  { REQ_LEFT_FIELD   |ID_FN  ,FN_Left_Field},
4278  { REQ_RIGHT_FIELD  |ID_FN  ,FN_Right_Field},
4279  { REQ_UP_FIELD     |ID_FN  ,FN_Up_Field},
4280  { REQ_DOWN_FIELD   |ID_FN  ,FN_Down_Field},
4281
4282  { REQ_NEXT_CHAR    |ID_IFN ,IFN_Next_Character},
4283  { REQ_PREV_CHAR    |ID_IFN ,IFN_Previous_Character},
4284  { REQ_NEXT_LINE    |ID_IFN ,IFN_Next_Line},
4285  { REQ_PREV_LINE    |ID_IFN ,IFN_Previous_Line},
4286  { REQ_NEXT_WORD    |ID_IFN ,IFN_Next_Word},
4287  { REQ_PREV_WORD    |ID_IFN ,IFN_Previous_Word},
4288  { REQ_BEG_FIELD    |ID_IFN ,IFN_Beginning_Of_Field},
4289  { REQ_END_FIELD    |ID_IFN ,IFN_End_Of_Field},
4290  { REQ_BEG_LINE     |ID_IFN ,IFN_Beginning_Of_Line},
4291  { REQ_END_LINE     |ID_IFN ,IFN_End_Of_Line},
4292  { REQ_LEFT_CHAR    |ID_IFN ,IFN_Left_Character},
4293  { REQ_RIGHT_CHAR   |ID_IFN ,IFN_Right_Character},
4294  { REQ_UP_CHAR      |ID_IFN ,IFN_Up_Character},
4295  { REQ_DOWN_CHAR    |ID_IFN ,IFN_Down_Character},
4296
4297  { REQ_NEW_LINE     |ID_FE  ,FE_New_Line},
4298  { REQ_INS_CHAR     |ID_FE  ,FE_Insert_Character},
4299  { REQ_INS_LINE     |ID_FE  ,FE_Insert_Line},
4300  { REQ_DEL_CHAR     |ID_FE  ,FE_Delete_Character},
4301  { REQ_DEL_PREV     |ID_FE  ,FE_Delete_Previous},
4302  { REQ_DEL_LINE     |ID_FE  ,FE_Delete_Line},
4303  { REQ_DEL_WORD     |ID_FE  ,FE_Delete_Word},
4304  { REQ_CLR_EOL      |ID_FE  ,FE_Clear_To_End_Of_Line},
4305  { REQ_CLR_EOF      |ID_FE  ,FE_Clear_To_End_Of_Field},
4306  { REQ_CLR_FIELD    |ID_FE  ,FE_Clear_Field},
4307
4308  { REQ_OVL_MODE     |ID_EM  ,EM_Overlay_Mode},
4309  { REQ_INS_MODE     |ID_EM  ,EM_Insert_Mode},
4310
4311  { REQ_SCR_FLINE    |ID_VSC ,VSC_Scroll_Line_Forward},
4312  { REQ_SCR_BLINE    |ID_VSC ,VSC_Scroll_Line_Backward},
4313  { REQ_SCR_FPAGE    |ID_VSC ,VSC_Scroll_Page_Forward},
4314  { REQ_SCR_BPAGE    |ID_VSC ,VSC_Scroll_Page_Backward},
4315  { REQ_SCR_FHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Forward},
4316  { REQ_SCR_BHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Backward},
4317
4318  { REQ_SCR_FCHAR    |ID_HSC ,HSC_Scroll_Char_Forward},
4319  { REQ_SCR_BCHAR    |ID_HSC ,HSC_Scroll_Char_Backward},
4320  { REQ_SCR_HFLINE   |ID_HSC ,HSC_Horizontal_Line_Forward},
4321  { REQ_SCR_HBLINE   |ID_HSC ,HSC_Horizontal_Line_Backward},
4322  { REQ_SCR_HFHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Forward},
4323  { REQ_SCR_HBHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Backward},
4324
4325  { REQ_VALIDATION   |ID_FV  ,FV_Validation},
4326
4327  { REQ_NEXT_CHOICE  |ID_CH  ,CR_Next_Choice},
4328  { REQ_PREV_CHOICE  |ID_CH  ,CR_Previous_Choice}
4329};
4330/* *INDENT-ON* */
4331
4332/*---------------------------------------------------------------------------
4333|   Facility      :  libnform
4334|   Function      :  int form_driver(FORM * form,int  c)
4335|
4336|   Description   :  This is the workhorse of the forms system. It checks
4337|                    to determine whether the character c is a request or
4338|                    data. If it is a request, the form driver executes
4339|                    the request and returns the result. If it is data
4340|                    (printable character), it enters the data into the
4341|                    current position in the current field. If it is not
4342|                    recognized, the form driver assumes it is an application
4343|                    defined command and returns E_UNKNOWN_COMMAND.
4344|                    Application defined command should be defined relative
4345|                    to MAX_FORM_COMMAND, the maximum value of a request.
4346|
4347|   Return Values :  E_OK              - success
4348|                    E_SYSTEM_ERROR    - system error
4349|                    E_BAD_ARGUMENT    - an argument is incorrect
4350|                    E_NOT_POSTED      - form is not posted
4351|                    E_INVALID_FIELD   - field contents are invalid
4352|                    E_BAD_STATE       - called from inside a hook routine
4353|                    E_REQUEST_DENIED  - request failed
4354|                    E_NOT_CONNECTED   - no fields are connected to the form
4355|                    E_UNKNOWN_COMMAND - command not known
4356+--------------------------------------------------------------------------*/
4357NCURSES_EXPORT(int)
4358form_driver(FORM *form, int c)
4359{
4360  const Binding_Info *BI = (Binding_Info *) 0;
4361  int res = E_UNKNOWN_COMMAND;
4362
4363  move_after_insert = TRUE;
4364
4365  T((T_CALLED("form_driver(%p,%d)"), (void *)form, c));
4366
4367  if (!form)
4368    RETURN(E_BAD_ARGUMENT);
4369
4370  if (!(form->field) || !(form->current))
4371    RETURN(E_NOT_CONNECTED);
4372
4373  assert(form->page);
4374
4375  if (c == FIRST_ACTIVE_MAGIC)
4376    {
4377      form->current = _nc_First_Active_Field(form);
4378      RETURN(E_OK);
4379    }
4380
4381  assert(form->current &&
4382	 form->current->buf &&
4383	 (form->current->form == form)
4384    );
4385
4386  if (form->status & _IN_DRIVER)
4387    RETURN(E_BAD_STATE);
4388
4389  if (!(form->status & _POSTED))
4390    RETURN(E_NOT_POSTED);
4391
4392  if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4393      ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4394    {
4395      TR(TRACE_CALLS, ("form_request %s", form_request_name(c)));
4396      BI = &(bindings[c - MIN_FORM_COMMAND]);
4397    }
4398
4399  if (BI)
4400    {
4401      typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4402      static const Generic_Method Generic_Methods[] =
4403      {
4404	Page_Navigation,	/* overloaded to call field&form hooks */
4405	Inter_Field_Navigation,	/* overloaded to call field hooks      */
4406	NULL,			/* Intra-Field is generic              */
4407	Vertical_Scrolling,	/* Overloaded to check multi-line      */
4408	Horizontal_Scrolling,	/* Overloaded to check single-line     */
4409	Field_Editing,		/* Overloaded to mark modification     */
4410	NULL,			/* Edit Mode is generic                */
4411	NULL,			/* Field Validation is generic         */
4412	NULL			/* Choice Request is generic           */
4413      };
4414      size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4415      size_t method = (size_t) ((BI->keycode >> ID_Shft) & 0xffff);	/* see ID_Mask */
4416
4417      if ((method >= nMethods) || !(BI->cmd))
4418	res = E_SYSTEM_ERROR;
4419      else
4420	{
4421	  Generic_Method fct = Generic_Methods[method];
4422
4423	  if (fct)
4424	    {
4425	      res = fct(BI->cmd, form);
4426	    }
4427	  else
4428	    {
4429	      res = (BI->cmd) (form);
4430	    }
4431	}
4432    }
4433#ifdef NCURSES_MOUSE_VERSION
4434  else if (KEY_MOUSE == c)
4435    {
4436      MEVENT event;
4437      WINDOW *win = form->win ? form->win : StdScreen(Get_Form_Screen(form));
4438      WINDOW *sub = form->sub ? form->sub : win;
4439
4440      getmouse(&event);
4441      if ((event.bstate & (BUTTON1_CLICKED |
4442			   BUTTON1_DOUBLE_CLICKED |
4443			   BUTTON1_TRIPLE_CLICKED))
4444	  && wenclose(win, event.y, event.x))
4445	{			/* we react only if the click was in the userwin, that means
4446				 * inside the form display area or at the decoration window.
4447				 */
4448	  int ry = event.y, rx = event.x;	/* screen coordinates */
4449
4450	  res = E_REQUEST_DENIED;
4451	  if (mouse_trafo(&ry, &rx, FALSE))
4452	    {			/* rx, ry are now "curses" coordinates */
4453	      if (ry < sub->_begy)
4454		{		/* we clicked above the display region; this is
4455				 * interpreted as "scroll up" request
4456				 */
4457		  if (event.bstate & BUTTON1_CLICKED)
4458		    res = form_driver(form, REQ_PREV_FIELD);
4459		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4460		    res = form_driver(form, REQ_PREV_PAGE);
4461		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4462		    res = form_driver(form, REQ_FIRST_FIELD);
4463		}
4464	      else if (ry > sub->_begy + sub->_maxy)
4465		{		/* we clicked below the display region; this is
4466				 * interpreted as "scroll down" request
4467				 */
4468		  if (event.bstate & BUTTON1_CLICKED)
4469		    res = form_driver(form, REQ_NEXT_FIELD);
4470		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4471		    res = form_driver(form, REQ_NEXT_PAGE);
4472		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4473		    res = form_driver(form, REQ_LAST_FIELD);
4474		}
4475	      else if (wenclose(sub, event.y, event.x))
4476		{		/* Inside the area we try to find the hit item */
4477		  int i;
4478
4479		  ry = event.y;
4480		  rx = event.x;
4481		  if (wmouse_trafo(sub, &ry, &rx, FALSE))
4482		    {
4483		      int min_field = form->page[form->curpage].pmin;
4484		      int max_field = form->page[form->curpage].pmax;
4485
4486		      for (i = min_field; i <= max_field; ++i)
4487			{
4488			  FIELD *field = form->field[i];
4489
4490			  if (Field_Is_Selectable(field)
4491			      && Field_encloses(field, ry, rx) == E_OK)
4492			    {
4493			      res = _nc_Set_Current_Field(form, field);
4494			      if (res == E_OK)
4495				res = _nc_Position_Form_Cursor(form);
4496			      if (res == E_OK
4497				  && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4498				res = E_UNKNOWN_COMMAND;
4499			      break;
4500			    }
4501			}
4502		    }
4503		}
4504	    }
4505	}
4506      else
4507	res = E_REQUEST_DENIED;
4508    }
4509#endif /* NCURSES_MOUSE_VERSION */
4510  else if (!(c & (~(int)MAX_REGULAR_CHARACTER)))
4511    {
4512      /*
4513       * If we're using 8-bit characters, iscntrl+isprint cover the whole set.
4514       * But with multibyte characters, there is a third possibility, i.e.,
4515       * parts of characters that build up into printable characters which are
4516       * not considered printable.
4517       *
4518       * FIXME: the wide-character branch should also use Check_Char().
4519       */
4520#if USE_WIDEC_SUPPORT
4521      if (!iscntrl(UChar(c)))
4522#else
4523      if (isprint(UChar(c)) &&
4524	  Check_Char(form, form->current, form->current->type, c,
4525		     (TypeArgument *)(form->current->arg)))
4526#endif
4527	res = Data_Entry(form, c);
4528    }
4529  _nc_Refresh_Current_Field(form);
4530  RETURN(res);
4531}
4532
4533# if USE_WIDEC_SUPPORT
4534/*---------------------------------------------------------------------------
4535|   Facility      :  libnform
4536|   Function      :  int form_driver_w(FORM * form,int type,wchar_t  c)
4537|
4538|   Description   :  This is the workhorse of the forms system.
4539|
4540|                    Input is either a key code (request) or a wide char
4541|                    returned by e.g. get_wch (). The type must be passed
4542|                    as well,so that we are able to determine whether the char
4543|                    is a multibyte char or a request.
4544
4545|                    If it is a request, the form driver executes
4546|                    the request and returns the result. If it is data
4547|                    (printable character), it enters the data into the
4548|                    current position in the current field. If it is not
4549|                    recognized, the form driver assumes it is an application
4550|                    defined command and returns E_UNKNOWN_COMMAND.
4551|                    Application defined command should be defined relative
4552|                    to MAX_FORM_COMMAND, the maximum value of a request.
4553|
4554|   Return Values :  E_OK              - success
4555|                    E_SYSTEM_ERROR    - system error
4556|                    E_BAD_ARGUMENT    - an argument is incorrect
4557|                    E_NOT_POSTED      - form is not posted
4558|                    E_INVALID_FIELD   - field contents are invalid
4559|                    E_BAD_STATE       - called from inside a hook routine
4560|                    E_REQUEST_DENIED  - request failed
4561|                    E_NOT_CONNECTED   - no fields are connected to the form
4562|                    E_UNKNOWN_COMMAND - command not known
4563+--------------------------------------------------------------------------*/
4564NCURSES_EXPORT(int)
4565form_driver_w(FORM *form, int type, wchar_t c)
4566{
4567  const Binding_Info *BI = (Binding_Info *) 0;
4568  int res = E_UNKNOWN_COMMAND;
4569
4570  T((T_CALLED("form_driver(%p,%d)"), (void *)form, (int)c));
4571
4572  if (!form)
4573    RETURN(E_BAD_ARGUMENT);
4574
4575  if (!(form->field))
4576    RETURN(E_NOT_CONNECTED);
4577
4578  assert(form->page);
4579
4580  if (c == (wchar_t)FIRST_ACTIVE_MAGIC)
4581    {
4582      form->current = _nc_First_Active_Field(form);
4583      RETURN(E_OK);
4584    }
4585
4586  assert(form->current &&
4587	 form->current->buf &&
4588	 (form->current->form == form)
4589    );
4590
4591  if (form->status & _IN_DRIVER)
4592    RETURN(E_BAD_STATE);
4593
4594  if (!(form->status & _POSTED))
4595    RETURN(E_NOT_POSTED);
4596
4597  /* check if this is a keycode or a (wide) char */
4598  if (type == KEY_CODE_YES)
4599    {
4600      if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4601	  ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4602	BI = &(bindings[c - MIN_FORM_COMMAND]);
4603    }
4604
4605  if (BI)
4606    {
4607      typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4608      static const Generic_Method Generic_Methods[] =
4609      {
4610	Page_Navigation,	/* overloaded to call field&form hooks */
4611	Inter_Field_Navigation,	/* overloaded to call field hooks      */
4612	NULL,			/* Intra-Field is generic              */
4613	Vertical_Scrolling,	/* Overloaded to check multi-line      */
4614	Horizontal_Scrolling,	/* Overloaded to check single-line     */
4615	Field_Editing,		/* Overloaded to mark modification     */
4616	NULL,			/* Edit Mode is generic                */
4617	NULL,			/* Field Validation is generic         */
4618	NULL			/* Choice Request is generic           */
4619      };
4620      size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4621      size_t method = (size_t) (BI->keycode >> ID_Shft) & 0xffff;	/* see ID_Mask */
4622
4623      if ((method >= nMethods) || !(BI->cmd))
4624	res = E_SYSTEM_ERROR;
4625      else
4626	{
4627	  Generic_Method fct = Generic_Methods[method];
4628
4629	  if (fct)
4630	    res = fct(BI->cmd, form);
4631	  else
4632	    res = (BI->cmd) (form);
4633	}
4634    }
4635#ifdef NCURSES_MOUSE_VERSION
4636  else if (KEY_MOUSE == c)
4637    {
4638      MEVENT event;
4639      WINDOW *win = form->win ? form->win : StdScreen(Get_Form_Screen(form));
4640      WINDOW *sub = form->sub ? form->sub : win;
4641
4642      getmouse(&event);
4643      if ((event.bstate & (BUTTON1_CLICKED |
4644			   BUTTON1_DOUBLE_CLICKED |
4645			   BUTTON1_TRIPLE_CLICKED))
4646	  && wenclose(win, event.y, event.x))
4647	{			/* we react only if the click was in the userwin, that means
4648				   * inside the form display area or at the decoration window.
4649				 */
4650	  int ry = event.y, rx = event.x;	/* screen coordinates */
4651
4652	  res = E_REQUEST_DENIED;
4653	  if (mouse_trafo(&ry, &rx, FALSE))
4654	    {			/* rx, ry are now "curses" coordinates */
4655	      if (ry < sub->_begy)
4656		{		/* we clicked above the display region; this is
4657				   * interpreted as "scroll up" request
4658				 */
4659		  if (event.bstate & BUTTON1_CLICKED)
4660		    res = form_driver(form, REQ_PREV_FIELD);
4661		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4662		    res = form_driver(form, REQ_PREV_PAGE);
4663		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4664		    res = form_driver(form, REQ_FIRST_FIELD);
4665		}
4666	      else if (ry > sub->_begy + sub->_maxy)
4667		{		/* we clicked below the display region; this is
4668				   * interpreted as "scroll down" request
4669				 */
4670		  if (event.bstate & BUTTON1_CLICKED)
4671		    res = form_driver(form, REQ_NEXT_FIELD);
4672		  else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4673		    res = form_driver(form, REQ_NEXT_PAGE);
4674		  else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4675		    res = form_driver(form, REQ_LAST_FIELD);
4676		}
4677	      else if (wenclose(sub, event.y, event.x))
4678		{		/* Inside the area we try to find the hit item */
4679		  int i;
4680
4681		  ry = event.y;
4682		  rx = event.x;
4683		  if (wmouse_trafo(sub, &ry, &rx, FALSE))
4684		    {
4685		      int min_field = form->page[form->curpage].pmin;
4686		      int max_field = form->page[form->curpage].pmax;
4687
4688		      for (i = min_field; i <= max_field; ++i)
4689			{
4690			  FIELD *field = form->field[i];
4691
4692			  if (Field_Is_Selectable(field)
4693			      && Field_encloses(field, ry, rx) == E_OK)
4694			    {
4695			      res = _nc_Set_Current_Field(form, field);
4696			      if (res == E_OK)
4697				res = _nc_Position_Form_Cursor(form);
4698			      if (res == E_OK
4699				  && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4700				res = E_UNKNOWN_COMMAND;
4701			      break;
4702			    }
4703			}
4704		    }
4705		}
4706	    }
4707	}
4708      else
4709	res = E_REQUEST_DENIED;
4710    }
4711#endif /* NCURSES_MOUSE_VERSION */
4712  else if (type == OK)
4713    {
4714      res = Data_Entry_w(form, c);
4715    }
4716
4717  _nc_Refresh_Current_Field(form);
4718  RETURN(res);
4719}
4720# endif	/* USE_WIDEC_SUPPORT */
4721
4722/*----------------------------------------------------------------------------
4723  Field-Buffer manipulation routines.
4724  The effects of setting a buffer are tightly coupled to the core of the form
4725  driver logic. This is especially true in the case of growable fields.
4726  So I don't separate this into a separate module.
4727  --------------------------------------------------------------------------*/
4728
4729/*---------------------------------------------------------------------------
4730|   Facility      :  libnform
4731|   Function      :  int set_field_buffer(FIELD *field,
4732|                                         int buffer, char *value)
4733|
4734|   Description   :  Set the given buffer of the field to the given value.
4735|                    Buffer 0 stores the displayed content of the field.
4736|                    For dynamic fields this may grow the fieldbuffers if
4737|                    the length of the value exceeds the current buffer
4738|                    length. For buffer 0 only printable values are allowed.
4739|                    For static fields, the value needs not to be zero ter-
4740|                    minated. It is copied up to the length of the buffer.
4741|
4742|   Return Values :  E_OK            - success
4743|                    E_BAD_ARGUMENT  - invalid argument
4744|                    E_SYSTEM_ERROR  - system error
4745+--------------------------------------------------------------------------*/
4746NCURSES_EXPORT(int)
4747set_field_buffer(FIELD *field, int buffer, const char *value)
4748{
4749  FIELD_CELL *p;
4750  int res = E_OK;
4751  int i;
4752  int len;
4753
4754#if USE_WIDEC_SUPPORT
4755  FIELD_CELL *widevalue = 0;
4756#endif
4757
4758  T((T_CALLED("set_field_buffer(%p,%d,%s)"), (void *)field, buffer, _nc_visbuf(value)));
4759
4760  if (!field || !value || ((buffer < 0) || (buffer > field->nbuf)))
4761    RETURN(E_BAD_ARGUMENT);
4762
4763  len = Buffer_Length(field);
4764
4765  if (Growable(field))
4766    {
4767      /* for a growable field we must assume zero terminated strings, because
4768         somehow we have to detect the length of what should be copied.
4769       */
4770      int vlen = (int)strlen(value);
4771
4772      if (vlen > len)
4773	{
4774	  if (!Field_Grown(field,
4775			   (int)(1 + (vlen - len) / ((field->rows + field->nrow)
4776						     * field->cols))))
4777	    RETURN(E_SYSTEM_ERROR);
4778
4779#if !USE_WIDEC_SUPPORT
4780	  len = vlen;
4781#endif
4782	}
4783    }
4784
4785  p = Address_Of_Nth_Buffer(field, buffer);
4786
4787#if USE_WIDEC_SUPPORT
4788  /*
4789   * Use addstr's logic for converting a string to an array of cchar_t's.
4790   * There should be a better way, but this handles nonspacing characters
4791   * and other special cases that we really do not want to handle here.
4792   */
4793#if NCURSES_EXT_FUNCS
4794  if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
4795#endif
4796    {
4797      delwin(field->working);
4798      field->working = newpad(1, Buffer_Length(field) + 1);
4799    }
4800  len = Buffer_Length(field);
4801  wclear(field->working);
4802  (void)mvwaddstr(field->working, 0, 0, value);
4803
4804  if ((widevalue = typeCalloc(FIELD_CELL, len + 1)) == 0)
4805    {
4806      RETURN(E_SYSTEM_ERROR);
4807    }
4808  else
4809    {
4810      for (i = 0; i < field->drows; ++i)
4811	{
4812	  (void)mvwin_wchnstr(field->working, 0, (int)i * field->dcols,
4813			      widevalue + ((int)i * field->dcols),
4814			      field->dcols);
4815	}
4816      for (i = 0; i < len; ++i)
4817	{
4818	  if (CharEq(myZEROS, widevalue[i]))
4819	    {
4820	      while (i < len)
4821		p[i++] = myBLANK;
4822	      break;
4823	    }
4824	  p[i] = widevalue[i];
4825	}
4826      free(widevalue);
4827    }
4828#else
4829  for (i = 0; i < len; ++i)
4830    {
4831      if (value[i] == '\0')
4832	{
4833	  while (i < len)
4834	    p[i++] = myBLANK;
4835	  break;
4836	}
4837      p[i] = value[i];
4838    }
4839#endif
4840
4841  if (buffer == 0)
4842    {
4843      int syncres;
4844
4845      if (((syncres = Synchronize_Field(field)) != E_OK) &&
4846	  (res == E_OK))
4847	res = syncres;
4848      if (((syncres = Synchronize_Linked_Fields(field)) != E_OK) &&
4849	  (res == E_OK))
4850	res = syncres;
4851    }
4852  RETURN(res);
4853}
4854
4855/*---------------------------------------------------------------------------
4856|   Facility      :  libnform
4857|   Function      :  char *field_buffer(const FIELD *field,int buffer)
4858|
4859|   Description   :  Return the address of the buffer for the field.
4860|
4861|   Return Values :  Pointer to buffer or NULL if arguments were invalid.
4862+--------------------------------------------------------------------------*/
4863NCURSES_EXPORT(char *)
4864field_buffer(const FIELD *field, int buffer)
4865{
4866  char *result = 0;
4867
4868  T((T_CALLED("field_buffer(%p,%d)"), (const void *)field, buffer));
4869
4870  if (field && (buffer >= 0) && (buffer <= field->nbuf))
4871    {
4872#if USE_WIDEC_SUPPORT
4873      FIELD_CELL *data = Address_Of_Nth_Buffer(field, buffer);
4874      size_t need = 0;
4875      int size = Buffer_Length(field);
4876      int n;
4877
4878      /* determine the number of bytes needed to store the expanded string */
4879      for (n = 0; n < size; ++n)
4880	{
4881	  if (!isWidecExt(data[n]) && data[n].chars[0] != L'\0')
4882	    {
4883	      mbstate_t state;
4884	      size_t next;
4885
4886	      init_mb(state);
4887	      next = _nc_wcrtomb(0, data[n].chars[0], &state);
4888	      if (next > 0)
4889		need += next;
4890	    }
4891	}
4892
4893      /* allocate a place to store the expanded string */
4894      if (field->expanded[buffer] != 0)
4895	free(field->expanded[buffer]);
4896      field->expanded[buffer] = typeMalloc(char, need + 1);
4897
4898      /*
4899       * Expand the multibyte data.
4900       *
4901       * It may also be multi-column data.  In that case, the data for a row
4902       * may be null-padded to align to the dcols/drows layout (or it may
4903       * contain embedded wide-character extensions).  Change the null-padding
4904       * to blanks as needed.
4905       */
4906      if ((result = field->expanded[buffer]) != 0)
4907	{
4908	  wclear(field->working);
4909	  wmove(field->working, 0, 0);
4910	  for (n = 0; n < size; ++n)
4911	    {
4912	      if (!isWidecExt(data[n]) && data[n].chars[0] != L'\0')
4913		wadd_wch(field->working, &data[n]);
4914	    }
4915	  wmove(field->working, 0, 0);
4916	  winnstr(field->working, result, (int)need);
4917	}
4918#else
4919      result = Address_Of_Nth_Buffer(field, buffer);
4920#endif
4921    }
4922  returnPtr(result);
4923}
4924
4925#if USE_WIDEC_SUPPORT
4926
4927/*---------------------------------------------------------------------------
4928| Convert a multibyte string to a wide-character string.  The result must be
4929| freed by the caller.
4930+--------------------------------------------------------------------------*/
4931NCURSES_EXPORT(wchar_t *)
4932_nc_Widen_String(char *source, int *lengthp)
4933{
4934  wchar_t *result = 0;
4935  wchar_t wch;
4936  size_t given = strlen(source);
4937  size_t tries;
4938  int pass;
4939  int status;
4940
4941#ifndef state_unused
4942  mbstate_t state;
4943#endif
4944
4945  for (pass = 0; pass < 2; ++pass)
4946    {
4947      unsigned need = 0;
4948      size_t passed = 0;
4949
4950      while (passed < given)
4951	{
4952	  bool found = FALSE;
4953
4954	  for (tries = 1, status = 0; tries <= (given - passed); ++tries)
4955	    {
4956	      int save = source[passed + tries];
4957
4958	      source[passed + tries] = 0;
4959	      reset_mbytes(state);
4960	      status = check_mbytes(wch, source + passed, tries, state);
4961	      source[passed + tries] = (char)save;
4962
4963	      if (status > 0)
4964		{
4965		  found = TRUE;
4966		  break;
4967		}
4968	    }
4969	  if (found)
4970	    {
4971	      if (pass)
4972		{
4973		  result[need] = wch;
4974		}
4975	      passed += (size_t) status;
4976	      ++need;
4977	    }
4978	  else
4979	    {
4980	      if (pass)
4981		{
4982		  result[need] = (wchar_t)source[passed];
4983		}
4984	      ++need;
4985	      ++passed;
4986	    }
4987	}
4988
4989      if (!pass)
4990	{
4991	  if (!need)
4992	    break;
4993	  result = typeCalloc(wchar_t, need);
4994
4995	  *lengthp = (int)need;
4996	  if (result == 0)
4997	    break;
4998	}
4999    }
5000
5001  return result;
5002}
5003#endif
5004
5005/* frm_driver.c ends here */
5006