ncurses 5.6 - patch 20070602
[ncurses.git] / form / frm_driver.c
1 /****************************************************************************
2  * Copyright (c) 1998-2006,2007 Free Software Foundation, Inc.              *
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13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
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24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28
29 /****************************************************************************
30  *   Author:  Juergen Pfeifer, 1995,1997                                    *
31  ****************************************************************************/
32
33 #include "form.priv.h"
34
35 MODULE_ID("$Id: frm_driver.c,v 1.82 2007/06/02 22:59:24 tom Exp $")
36
37 /*----------------------------------------------------------------------------
38   This is the core module of the form library. It contains the majority
39   of the driver routines as well as the form_driver function.
40
41   Essentially this module is nearly the whole library. This is because
42   all the functions in this module depends on some others in the module,
43   so it makes no sense to split them into separate files because they
44   will always be linked together. The only acceptable concern is turnaround
45   time for this module, but now we have all Pentiums or RISCs, so what!
46
47   The driver routines are grouped into nine generic categories:
48
49    a)   Page Navigation            ( all functions prefixed by PN_ )
50         The current page of the form is left and some new page is
51         entered.
52    b)   Inter-Field Navigation     ( all functions prefixed by FN_ )
53         The current field of the form is left and some new field is
54         entered.
55    c)   Intra-Field Navigation     ( all functions prefixed by IFN_ )
56         The current position in the current field is changed.
57    d)   Vertical Scrolling         ( all functions prefixed by VSC_ )
58         Essentially this is a specialization of Intra-Field navigation.
59         It has to check for a multi-line field.
60    e)   Horizontal Scrolling       ( all functions prefixed by HSC_ )
61         Essentially this is a specialization of Intra-Field navigation.
62         It has to check for a single-line field.
63    f)   Field Editing              ( all functions prefixed by FE_ )
64         The content of the current field is changed
65    g)   Edit Mode requests         ( all functions prefixed by EM_ )
66         Switching between insert and overlay mode
67    h)   Field-Validation requests  ( all functions prefixed by FV_ )
68         Perform verifications of the field.
69    i)   Choice requests            ( all functions prefixed by CR_ )
70         Requests to enumerate possible field values
71   --------------------------------------------------------------------------*/
72
73 /*----------------------------------------------------------------------------
74   Some remarks on the placements of assert() macros :
75   I use them only on "strategic" places, i.e. top level entries where
76   I want to make sure that things are set correctly. Throughout subordinate
77   routines I omit them mostly.
78   --------------------------------------------------------------------------*/
79
80 /*
81 Some options that may effect compatibility in behavior to SVr4 forms,
82 but they are here to allow a more intuitive and user friendly behavior of
83 our form implementation. This doesn't affect the API, so we feel it is
84 uncritical.
85
86 The initial implementation tries to stay very close with the behavior
87 of the original SVr4 implementation, although in some areas it is quite
88 clear that this isn't the most appropriate way. As far as possible this
89 sources will allow you to build a forms lib that behaves quite similar
90 to SVr4, but now and in the future we will give you better options.
91 Perhaps at some time we will make this configurable at runtime.
92 */
93
94 /* Implement a more user-friendly previous/next word behavior */
95 #define FRIENDLY_PREV_NEXT_WORD (1)
96 /* Fix the wrong behavior for forms with all fields inactive */
97 #define FIX_FORM_INACTIVE_BUG (1)
98 /* Allow dynamic field growth also when navigating past the end */
99 #define GROW_IF_NAVIGATE (1)
100
101 #if USE_WIDEC_SUPPORT
102 #define myADDNSTR(w, s, n) wadd_wchnstr(w, s, n)
103 #define myINSNSTR(w, s, n) wins_wchnstr(w, s, n)
104 #define myINNSTR(w, s, n)  fix_wchnstr(w, s, n)
105 #define myWCWIDTH(w, y, x) cell_width(w, y, x)
106 #else
107 #define myADDNSTR(w, s, n) waddnstr(w, s, n)
108 #define myINSNSTR(w, s, n) winsnstr(w, s, n)
109 #define myINNSTR(w, s, n)  winnstr(w, s, n)
110 #define myWCWIDTH(w, y, x) 1
111 #endif
112
113 /*----------------------------------------------------------------------------
114   Forward references to some internally used static functions
115   --------------------------------------------------------------------------*/
116 static int Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form);
117 static int FN_Next_Field(FORM *form);
118 static int FN_Previous_Field(FORM *form);
119 static int FE_New_Line(FORM *);
120 static int FE_Delete_Previous(FORM *);
121
122 /*----------------------------------------------------------------------------
123   Macro Definitions.
124
125   Some Remarks on that: I use the convention to use UPPERCASE for constants
126   defined by Macros. If I provide a macro as a kind of inline routine to
127   provide some logic, I use my Upper_Lower case style.
128   --------------------------------------------------------------------------*/
129
130 /* Calculate the position of a single row in a field buffer */
131 #define Position_Of_Row_In_Buffer(field,row) ((row)*(field)->dcols)
132
133 /* Calculate start address for the fields buffer# N */
134 #define Address_Of_Nth_Buffer(field,N) \
135   ((field)->buf + (N)*(1+Buffer_Length(field)))
136
137 /* Calculate the start address of the row in the fields specified buffer# N */
138 #define Address_Of_Row_In_Nth_Buffer(field,N,row) \
139   (Address_Of_Nth_Buffer(field,N) + Position_Of_Row_In_Buffer(field,row))
140
141 /* Calculate the start address of the row in the fields primary buffer */
142 #define Address_Of_Row_In_Buffer(field,row) \
143   Address_Of_Row_In_Nth_Buffer(field,0,row)
144
145 /* Calculate the start address of the row in the forms current field
146    buffer# N */
147 #define Address_Of_Current_Row_In_Nth_Buffer(form,N) \
148    Address_Of_Row_In_Nth_Buffer((form)->current,N,(form)->currow)
149
150 /* Calculate the start address of the row in the forms current field
151    primary buffer */
152 #define Address_Of_Current_Row_In_Buffer(form) \
153    Address_Of_Current_Row_In_Nth_Buffer(form,0)
154
155 /* Calculate the address of the cursor in the forms current field
156    primary buffer */
157 #define Address_Of_Current_Position_In_Nth_Buffer(form,N) \
158    (Address_Of_Current_Row_In_Nth_Buffer(form,N) + (form)->curcol)
159
160 /* Calculate the address of the cursor in the forms current field
161    buffer# N */
162 #define Address_Of_Current_Position_In_Buffer(form) \
163   Address_Of_Current_Position_In_Nth_Buffer(form,0)
164
165 /* Logic to decide whether or not a field is actually a field with
166    vertical or horizontal scrolling */
167 #define Is_Scroll_Field(field)          \
168    (((field)->drows > (field)->rows) || \
169     ((field)->dcols > (field)->cols))
170
171 /* Logic to decide whether or not a field needs to have an individual window
172    instead of a derived window because it contains invisible parts.
173    This is true for non-public fields and for scrollable fields. */
174 #define Has_Invisible_Parts(field)     \
175   (!((field)->opts & O_PUBLIC)      || \
176    Is_Scroll_Field(field))
177
178 /* Logic to decide whether or not a field needs justification */
179 #define Justification_Allowed(field)        \
180    (((field)->just != NO_JUSTIFICATION)  && \
181     (Single_Line_Field(field))           && \
182     (((field)->dcols == (field)->cols)   && \
183     ((field)->opts & O_STATIC))             )
184
185 /* Logic to determine whether or not a dynamic field may still grow */
186 #define Growable(field) ((field)->status & _MAY_GROW)
187
188 /* Macro to set the attributes for a fields window */
189 #define Set_Field_Window_Attributes(field,win) \
190 (  wbkgdset((win),(chtype)((field)->pad | (field)->back)), \
191    wattrset((win),(field)->fore) )
192
193 /* Logic to decide whether or not a field really appears on the form */
194 #define Field_Really_Appears(field)         \
195   ((field->form)                          &&\
196    (field->form->status & _POSTED)        &&\
197    (field->opts & O_VISIBLE)              &&\
198    (field->page == field->form->curpage))
199
200 /* Logic to determine whether or not we are on the first position in the
201    current field */
202 #define First_Position_In_Current_Field(form) \
203   (((form)->currow==0) && ((form)->curcol==0))
204
205 #define Minimum(a,b) (((a)<=(b)) ? (a) : (b))
206 #define Maximum(a,b) (((a)>=(b)) ? (a) : (b))
207
208 /*----------------------------------------------------------------------------
209   Useful constants
210   --------------------------------------------------------------------------*/
211 static FIELD_CELL myBLANK = BLANK;
212 static FIELD_CELL myZEROS;
213
214 #ifdef TRACE
215 static void
216 check_pos(FORM *form, int lineno)
217 {
218   int y, x;
219
220   if (form && form->w)
221     {
222       getyx(form->w, y, x);
223       if (y != form->currow || x != form->curcol)
224         {
225           T(("CHECKPOS %s@%d have position %d,%d vs want %d,%d",
226              __FILE__, lineno,
227              y, x,
228              form->currow, form->curcol));
229         }
230     }
231 }
232 #define CHECKPOS(form) check_pos(form, __LINE__)
233 #else
234 #define CHECKPOS(form)          /* nothing */
235 #endif
236
237 /*----------------------------------------------------------------------------
238   Wide-character special functions
239   --------------------------------------------------------------------------*/
240 #if USE_WIDEC_SUPPORT
241 /* like winsnstr */
242 static int
243 wins_wchnstr(WINDOW *w, cchar_t *s, int n)
244 {
245   int code = ERR;
246   int y, x;
247
248   while (n-- > 0)
249     {
250       getyx(w, y, x);
251       if ((code = wins_wch(w, s++)) != OK)
252         break;
253       if ((code = wmove(w, y, x + 1)) != OK)
254         break;
255     }
256   return code;
257 }
258
259 /* win_wchnstr is inconsistent with winnstr, since it returns OK rather than
260  * the number of items transferred.
261  */
262 static int
263 fix_wchnstr(WINDOW *w, cchar_t *s, int n)
264 {
265   int x;
266
267   win_wchnstr(w, s, n);
268   /*
269    * This function is used to extract the text only from the window.
270    * Strip attributes and color from the string so they will not be added
271    * back when copying the string to the window.
272    */
273   for (x = 0; x < n; ++x)
274     {
275       RemAttr(s[x], A_ATTRIBUTES);
276       SetPair(s[x], 0);
277     }
278   return n;
279 }
280
281 /*
282  * Returns the column of the base of the given cell.
283  */
284 static int
285 cell_base(WINDOW *win, int y, int x)
286 {
287   int result = x;
288
289   while (LEGALYX(win, y, x))
290     {
291       cchar_t *data = &(win->_line[y].text[x]);
292
293       if (isWidecBase(CHDEREF(data)) || !isWidecExt(CHDEREF(data)))
294         {
295           result = x;
296           break;
297         }
298       --x;
299     }
300   return result;
301 }
302
303 /*
304  * Returns the number of columns needed for the given cell in a window.
305  */
306 static int
307 cell_width(WINDOW *win, int y, int x)
308 {
309   int result = 1;
310
311   if (LEGALYX(win, y, x))
312     {
313       cchar_t *data = &(win->_line[y].text[x]);
314
315       if (isWidecExt(CHDEREF(data)))
316         {
317           /* recur, providing the number of columns to the next character */
318           result = cell_width(win, y, x - 1);
319         }
320       else
321         {
322           result = wcwidth(CharOf(CHDEREF(data)));
323         }
324     }
325   return result;
326 }
327
328 /*
329  * There is no wide-character function such as wdel_wch(), so we must find
330  * all of the cells that comprise a multi-column character and delete them
331  * one-by-one.
332  */
333 static void
334 delete_char(FORM *form)
335 {
336   int cells = cell_width(form->w, form->currow, form->curcol);
337
338   form->curcol = cell_base(form->w, form->currow, form->curcol);
339   wmove(form->w, form->currow, form->curcol);
340   while (cells-- > 0)
341     {
342       wdelch(form->w);
343     }
344 }
345 #define DeleteChar(form) delete_char(form)
346 #else
347 #define DeleteChar(form) \
348           wmove((form)->w, (form)->currow, (form)->curcol), \
349           wdelch((form)->w)
350 #endif
351
352 /*---------------------------------------------------------------------------
353 |   Facility      :  libnform
354 |   Function      :  static char *Get_Start_Of_Data(char * buf, int blen)
355 |
356 |   Description   :  Return pointer to first non-blank position in buffer.
357 |                    If buffer is empty return pointer to buffer itself.
358 |
359 |   Return Values :  Pointer to first non-blank position in buffer
360 +--------------------------------------------------------------------------*/
361 NCURSES_INLINE static FIELD_CELL *
362 Get_Start_Of_Data(FIELD_CELL *buf, int blen)
363 {
364   FIELD_CELL *p = buf;
365   FIELD_CELL *end = &buf[blen];
366
367   assert(buf && blen >= 0);
368   while ((p < end) && ISBLANK(*p))
369     p++;
370   return ((p == end) ? buf : p);
371 }
372
373 /*---------------------------------------------------------------------------
374 |   Facility      :  libnform
375 |   Function      :  static char *After_End_Of_Data(char * buf, int blen)
376 |
377 |   Description   :  Return pointer after last non-blank position in buffer.
378 |                    If buffer is empty, return pointer to buffer itself.
379 |
380 |   Return Values :  Pointer to position after last non-blank position in
381 |                    buffer.
382 +--------------------------------------------------------------------------*/
383 NCURSES_INLINE static FIELD_CELL *
384 After_End_Of_Data(FIELD_CELL *buf, int blen)
385 {
386   FIELD_CELL *p = &buf[blen];
387
388   assert(buf && blen >= 0);
389   while ((p > buf) && ISBLANK(p[-1]))
390     p--;
391   return (p);
392 }
393
394 /*---------------------------------------------------------------------------
395 |   Facility      :  libnform
396 |   Function      :  static char *Get_First_Whitespace_Character(
397 |                                     char * buf, int   blen)
398 |
399 |   Description   :  Position to the first whitespace character.
400 |
401 |   Return Values :  Pointer to first whitespace character in buffer.
402 +--------------------------------------------------------------------------*/
403 NCURSES_INLINE static FIELD_CELL *
404 Get_First_Whitespace_Character(FIELD_CELL *buf, int blen)
405 {
406   FIELD_CELL *p = buf;
407   FIELD_CELL *end = &p[blen];
408
409   assert(buf && blen >= 0);
410   while ((p < end) && !ISBLANK(*p))
411     p++;
412   return ((p == end) ? buf : p);
413 }
414
415 /*---------------------------------------------------------------------------
416 |   Facility      :  libnform
417 |   Function      :  static char *After_Last_Whitespace_Character(
418 |                                     char * buf, int blen)
419 |
420 |   Description   :  Get the position after the last whitespace character.
421 |
422 |   Return Values :  Pointer to position after last whitespace character in
423 |                    buffer.
424 +--------------------------------------------------------------------------*/
425 NCURSES_INLINE static FIELD_CELL *
426 After_Last_Whitespace_Character(FIELD_CELL *buf, int blen)
427 {
428   FIELD_CELL *p = &buf[blen];
429
430   assert(buf && blen >= 0);
431   while ((p > buf) && !ISBLANK(p[-1]))
432     p--;
433   return (p);
434 }
435
436 /* Set this to 1 to use the div_t version. This is a good idea if your
437    compiler has an intrinsic div() support. Unfortunately GNU-C has it
438    not yet.
439    N.B.: This only works if form->curcol follows immediately form->currow
440          and both are of type int.
441 */
442 #define USE_DIV_T (0)
443
444 /*---------------------------------------------------------------------------
445 |   Facility      :  libnform
446 |   Function      :  static void Adjust_Cursor_Position(
447 |                                       FORM * form, const char * pos)
448 |
449 |   Description   :  Set current row and column of the form to values
450 |                    corresponding to the buffer position.
451 |
452 |   Return Values :  -
453 +--------------------------------------------------------------------------*/
454 NCURSES_INLINE static void
455 Adjust_Cursor_Position(FORM *form, const FIELD_CELL *pos)
456 {
457   FIELD *field;
458   int idx;
459
460   field = form->current;
461   assert(pos >= field->buf && field->dcols > 0);
462   idx = (int)(pos - field->buf);
463 #if USE_DIV_T
464   *((div_t *) & (form->currow)) = div(idx, field->dcols);
465 #else
466   form->currow = idx / field->dcols;
467   form->curcol = idx - field->cols * form->currow;
468 #endif
469   if (field->drows < form->currow)
470     form->currow = 0;
471 }
472
473 /*---------------------------------------------------------------------------
474 |   Facility      :  libnform
475 |   Function      :  static void Buffer_To_Window(
476 |                                      const FIELD  * field,
477 |                                      WINDOW * win)
478 |
479 |   Description   :  Copy the buffer to the window. If it is a multi-line
480 |                    field, the buffer is split to the lines of the
481 |                    window without any editing.
482 |
483 |   Return Values :  -
484 +--------------------------------------------------------------------------*/
485 static void
486 Buffer_To_Window(const FIELD *field, WINDOW *win)
487 {
488   int width, height;
489   int y, x;
490   int len;
491   int row;
492   FIELD_CELL *pBuffer;
493
494   assert(win && field);
495
496   getyx(win, y, x);
497   width = getmaxx(win);
498   height = getmaxy(win);
499
500   for (row = 0, pBuffer = field->buf;
501        row < height;
502        row++, pBuffer += width)
503     {
504       if ((len = (int)(After_End_Of_Data(pBuffer, width) - pBuffer)) > 0)
505         {
506           wmove(win, row, 0);
507           myADDNSTR(win, pBuffer, len);
508         }
509     }
510   wmove(win, y, x);
511 }
512
513 /*---------------------------------------------------------------------------
514 |   Facility      :  libnform
515 |   Function      :  static void Window_To_Buffer(
516 |                                          WINDOW * win,
517 |                                          FIELD  * field)
518 |
519 |   Description   :  Copy the content of the window into the buffer.
520 |                    The multiple lines of a window are simply
521 |                    concatenated into the buffer. Pad characters in
522 |                    the window will be replaced by blanks in the buffer.
523 |
524 |   Return Values :  -
525 +--------------------------------------------------------------------------*/
526 static void
527 Window_To_Buffer(WINDOW *win, FIELD *field)
528 {
529   int pad;
530   int len = 0;
531   FIELD_CELL *p;
532   int row, height;
533
534   assert(win && field && field->buf);
535
536   pad = field->pad;
537   p = field->buf;
538   height = getmaxy(win);
539
540   for (row = 0; (row < height) && (row < field->drows); row++)
541     {
542       wmove(win, row, 0);
543       len += myINNSTR(win, p + len, field->dcols);
544     }
545   p[len] = myZEROS;
546
547   /* replace visual padding character by blanks in buffer */
548   if (pad != C_BLANK)
549     {
550       int i;
551
552       for (i = 0; i < len; i++, p++)
553         {
554           if ((unsigned long)CharOf(*p) == ChCharOf(pad)
555 #if USE_WIDEC_SUPPORT
556               && p->chars[1] == 0
557 #endif
558             )
559             *p = myBLANK;
560         }
561     }
562 }
563
564 /*---------------------------------------------------------------------------
565 |   Facility      :  libnform
566 |   Function      :  static void Synchronize_Buffer(FORM * form)
567 |
568 |   Description   :  If there was a change, copy the content of the
569 |                    window into the buffer, so the buffer is synchronized
570 |                    with the windows content. We have to indicate that the
571 |                    buffer needs validation due to the change.
572 |
573 |   Return Values :  -
574 +--------------------------------------------------------------------------*/
575 NCURSES_INLINE static void
576 Synchronize_Buffer(FORM *form)
577 {
578   if (form->status & _WINDOW_MODIFIED)
579     {
580       form->status &= ~_WINDOW_MODIFIED;
581       form->status |= _FCHECK_REQUIRED;
582       Window_To_Buffer(form->w, form->current);
583       wmove(form->w, form->currow, form->curcol);
584     }
585 }
586
587 /*---------------------------------------------------------------------------
588 |   Facility      :  libnform
589 |   Function      :  static bool Field_Grown( FIELD *field, int amount)
590 |
591 |   Description   :  This function is called for growable dynamic fields
592 |                    only. It has to increase the buffers and to allocate
593 |                    a new window for this field.
594 |                    This function has the side effect to set a new
595 |                    field-buffer pointer, the dcols and drows values
596 |                    as well as a new current Window for the field.
597 |
598 |   Return Values :  TRUE     - field successfully increased
599 |                    FALSE    - there was some error
600 +--------------------------------------------------------------------------*/
601 static bool
602 Field_Grown(FIELD *field, int amount)
603 {
604   bool result = FALSE;
605
606   if (field && Growable(field))
607     {
608       bool single_line_field = Single_Line_Field(field);
609       int old_buflen = Buffer_Length(field);
610       int new_buflen;
611       int old_dcols = field->dcols;
612       int old_drows = field->drows;
613       FIELD_CELL *oldbuf = field->buf;
614       FIELD_CELL *newbuf;
615
616       int growth;
617       FORM *form = field->form;
618       bool need_visual_update = ((form != (FORM *)0) &&
619                                  (form->status & _POSTED) &&
620                                  (form->current == field));
621
622       if (need_visual_update)
623         Synchronize_Buffer(form);
624
625       if (single_line_field)
626         {
627           growth = field->cols * amount;
628           if (field->maxgrow)
629             growth = Minimum(field->maxgrow - field->dcols, growth);
630           field->dcols += growth;
631           if (field->dcols == field->maxgrow)
632             field->status &= ~_MAY_GROW;
633         }
634       else
635         {
636           growth = (field->rows + field->nrow) * amount;
637           if (field->maxgrow)
638             growth = Minimum(field->maxgrow - field->drows, growth);
639           field->drows += growth;
640           if (field->drows == field->maxgrow)
641             field->status &= ~_MAY_GROW;
642         }
643       /* drows, dcols changed, so we get really the new buffer length */
644       new_buflen = Buffer_Length(field);
645       newbuf = (FIELD_CELL *)malloc(Total_Buffer_Size(field));
646       if (!newbuf)
647         {
648           /* restore to previous state */
649           field->dcols = old_dcols;
650           field->drows = old_drows;
651           if ((single_line_field && (field->dcols != field->maxgrow)) ||
652               (!single_line_field && (field->drows != field->maxgrow)))
653             field->status |= _MAY_GROW;
654         }
655       else
656         {
657           /* Copy all the buffers.  This is the reason why we can't just use
658            * realloc().
659            */
660           int i, j;
661           FIELD_CELL *old_bp;
662           FIELD_CELL *new_bp;
663
664           result = TRUE;        /* allow sharing of recovery on failure */
665
666           T((T_CREATE("fieldcell %p"), newbuf));
667           field->buf = newbuf;
668           for (i = 0; i <= field->nbuf; i++)
669             {
670               new_bp = Address_Of_Nth_Buffer(field, i);
671               old_bp = oldbuf + i * (1 + old_buflen);
672               for (j = 0; j < old_buflen; ++j)
673                 new_bp[j] = old_bp[j];
674               while (j < new_buflen)
675                 new_bp[j++] = myBLANK;
676               new_bp[new_buflen] = myZEROS;
677             }
678
679 #if USE_WIDEC_SUPPORT
680           if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
681             result = FALSE;
682 #endif
683
684           if (need_visual_update && result)
685             {
686               WINDOW *new_window = newpad(field->drows, field->dcols);
687
688               if (new_window != 0)
689                 {
690                   assert(form != (FORM *)0);
691                   if (form->w)
692                     delwin(form->w);
693                   form->w = new_window;
694                   Set_Field_Window_Attributes(field, form->w);
695                   werase(form->w);
696                   Buffer_To_Window(field, form->w);
697                   untouchwin(form->w);
698                   wmove(form->w, form->currow, form->curcol);
699                 }
700               else
701                 result = FALSE;
702             }
703
704           if (result)
705             {
706               free(oldbuf);
707               /* reflect changes in linked fields */
708               if (field != field->link)
709                 {
710                   FIELD *linked_field;
711
712                   for (linked_field = field->link;
713                        linked_field != field;
714                        linked_field = linked_field->link)
715                     {
716                       linked_field->buf = field->buf;
717                       linked_field->drows = field->drows;
718                       linked_field->dcols = field->dcols;
719                     }
720                 }
721             }
722           else
723             {
724               /* restore old state */
725               field->dcols = old_dcols;
726               field->drows = old_drows;
727               field->buf = oldbuf;
728               if ((single_line_field &&
729                    (field->dcols != field->maxgrow)) ||
730                   (!single_line_field &&
731                    (field->drows != field->maxgrow)))
732                 field->status |= _MAY_GROW;
733               free(newbuf);
734             }
735         }
736     }
737   return (result);
738 }
739
740 #ifdef NCURSES_MOUSE_VERSION
741 /*---------------------------------------------------------------------------
742 |   Facility      :  libnform
743 |   Function      :  int Field_encloses(FIELD *field, int ry, int rx)
744 |
745 |   Description   :  Check if the given coordinates lie within the given field.
746 |
747 |   Return Values :  E_OK              - success
748 |                    E_BAD_ARGUMENT    - invalid form pointer
749 |                    E_SYSTEM_ERROR    - form has no current field or
750 |                                        field-window
751 +--------------------------------------------------------------------------*/
752 static int
753 Field_encloses(FIELD *field, int ry, int rx)
754 {
755   T((T_CALLED("Field_encloses(%p)"), field));
756   if (field != 0
757       && field->frow <= ry
758       && (field->frow + field->rows) > ry
759       && field->fcol <= rx
760       && (field->fcol + field->cols) > rx)
761     {
762       RETURN(E_OK);
763     }
764   RETURN(E_INVALID_FIELD);
765 }
766 #endif
767
768 /*---------------------------------------------------------------------------
769 |   Facility      :  libnform
770 |   Function      :  int _nc_Position_Form_Cursor(FORM * form)
771 |
772 |   Description   :  Position the cursor in the window for the current
773 |                    field to be in sync. with the currow and curcol
774 |                    values.
775 |
776 |   Return Values :  E_OK              - success
777 |                    E_BAD_ARGUMENT    - invalid form pointer
778 |                    E_SYSTEM_ERROR    - form has no current field or
779 |                                        field-window
780 +--------------------------------------------------------------------------*/
781 NCURSES_EXPORT(int)
782 _nc_Position_Form_Cursor(FORM *form)
783 {
784   FIELD *field;
785   WINDOW *formwin;
786
787   if (!form)
788     return (E_BAD_ARGUMENT);
789
790   if (!form->w || !form->current)
791     return (E_SYSTEM_ERROR);
792
793   field = form->current;
794   formwin = Get_Form_Window(form);
795
796   wmove(form->w, form->currow, form->curcol);
797   if (Has_Invisible_Parts(field))
798     {
799       /* in this case fieldwin isn't derived from formwin, so we have
800          to move the cursor in formwin by hand... */
801       wmove(formwin,
802             field->frow + form->currow - form->toprow,
803             field->fcol + form->curcol - form->begincol);
804       wcursyncup(formwin);
805     }
806   else
807     wcursyncup(form->w);
808   return (E_OK);
809 }
810
811 /*---------------------------------------------------------------------------
812 |   Facility      :  libnform
813 |   Function      :  int _nc_Refresh_Current_Field(FORM * form)
814 |
815 |   Description   :  Propagate the changes in the fields window to the
816 |                    window of the form.
817 |
818 |   Return Values :  E_OK              - on success
819 |                    E_BAD_ARGUMENT    - invalid form pointer
820 |                    E_SYSTEM_ERROR    - general error
821 +--------------------------------------------------------------------------*/
822 NCURSES_EXPORT(int)
823 _nc_Refresh_Current_Field(FORM *form)
824 {
825   WINDOW *formwin;
826   FIELD *field;
827
828   T((T_CALLED("_nc_Refresh_Current_Field(%p)"), form));
829
830   if (!form)
831     RETURN(E_BAD_ARGUMENT);
832
833   if (!form->w || !form->current)
834     RETURN(E_SYSTEM_ERROR);
835
836   field = form->current;
837   formwin = Get_Form_Window(form);
838
839   if (field->opts & O_PUBLIC)
840     {
841       if (Is_Scroll_Field(field))
842         {
843           /* Again, in this case the fieldwin isn't derived from formwin,
844              so we have to perform a copy operation. */
845           if (Single_Line_Field(field))
846             {
847               /* horizontal scrolling */
848               if (form->curcol < form->begincol)
849                 form->begincol = form->curcol;
850               else
851                 {
852                   if (form->curcol >= (form->begincol + field->cols))
853                     form->begincol = form->curcol - field->cols + 1;
854                 }
855               copywin(form->w,
856                       formwin,
857                       0,
858                       form->begincol,
859                       field->frow,
860                       field->fcol,
861                       field->frow,
862                       field->cols + field->fcol - 1,
863                       0);
864             }
865           else
866             {
867               /* A multi-line, i.e. vertical scrolling field */
868               int row_after_bottom, first_modified_row, first_unmodified_row;
869
870               if (field->drows > field->rows)
871                 {
872                   row_after_bottom = form->toprow + field->rows;
873                   if (form->currow < form->toprow)
874                     {
875                       form->toprow = form->currow;
876                       field->status |= _NEWTOP;
877                     }
878                   if (form->currow >= row_after_bottom)
879                     {
880                       form->toprow = form->currow - field->rows + 1;
881                       field->status |= _NEWTOP;
882                     }
883                   if (field->status & _NEWTOP)
884                     {
885                       /* means we have to copy whole range */
886                       first_modified_row = form->toprow;
887                       first_unmodified_row = first_modified_row + field->rows;
888                       field->status &= ~_NEWTOP;
889                     }
890                   else
891                     {
892                       /* we try to optimize : finding the range of touched
893                          lines */
894                       first_modified_row = form->toprow;
895                       while (first_modified_row < row_after_bottom)
896                         {
897                           if (is_linetouched(form->w, first_modified_row))
898                             break;
899                           first_modified_row++;
900                         }
901                       first_unmodified_row = first_modified_row;
902                       while (first_unmodified_row < row_after_bottom)
903                         {
904                           if (!is_linetouched(form->w, first_unmodified_row))
905                             break;
906                           first_unmodified_row++;
907                         }
908                     }
909                 }
910               else
911                 {
912                   first_modified_row = form->toprow;
913                   first_unmodified_row = first_modified_row + field->rows;
914                 }
915               if (first_unmodified_row != first_modified_row)
916                 copywin(form->w,
917                         formwin,
918                         first_modified_row,
919                         0,
920                         field->frow + first_modified_row - form->toprow,
921                         field->fcol,
922                         field->frow + first_unmodified_row - form->toprow - 1,
923                         field->cols + field->fcol - 1,
924                         0);
925             }
926           wsyncup(formwin);
927         }
928       else
929         {
930           /* if the field-window is simply a derived window, i.e. contains no
931            * invisible parts, the whole thing is trivial
932            */
933           wsyncup(form->w);
934         }
935     }
936   untouchwin(form->w);
937   returnCode(_nc_Position_Form_Cursor(form));
938 }
939
940 /*---------------------------------------------------------------------------
941 |   Facility      :  libnform
942 |   Function      :  static void Perform_Justification(
943 |                                        FIELD  * field,
944 |                                        WINDOW * win)
945 |
946 |   Description   :  Output field with requested justification
947 |
948 |   Return Values :  -
949 +--------------------------------------------------------------------------*/
950 static void
951 Perform_Justification(FIELD *field, WINDOW *win)
952 {
953   FIELD_CELL *bp;
954   int len;
955   int col = 0;
956
957   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
958   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
959
960   if (len > 0)
961     {
962       assert(win && (field->drows == 1) && (field->dcols == field->cols));
963
964       switch (field->just)
965         {
966         case JUSTIFY_LEFT:
967           break;
968         case JUSTIFY_CENTER:
969           col = (field->cols - len) / 2;
970           break;
971         case JUSTIFY_RIGHT:
972           col = field->cols - len;
973           break;
974         default:
975           break;
976         }
977
978       wmove(win, 0, col);
979       myADDNSTR(win, bp, len);
980     }
981 }
982
983 /*---------------------------------------------------------------------------
984 |   Facility      :  libnform
985 |   Function      :  static void Undo_Justification(
986 |                                     FIELD  * field,
987 |                                     WINDOW * win)
988 |
989 |   Description   :  Display field without any justification, i.e.
990 |                    left justified
991 |
992 |   Return Values :  -
993 +--------------------------------------------------------------------------*/
994 static void
995 Undo_Justification(FIELD *field, WINDOW *win)
996 {
997   FIELD_CELL *bp;
998   int len;
999
1000   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
1001   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
1002
1003   if (len > 0)
1004     {
1005       assert(win);
1006       wmove(win, 0, 0);
1007       myADDNSTR(win, bp, len);
1008     }
1009 }
1010
1011 /*---------------------------------------------------------------------------
1012 |   Facility      :  libnform
1013 |   Function      :  static bool Check_Char(
1014 |                                           FIELDTYPE * typ,
1015 |                                           int ch,
1016 |                                           TypeArgument *argp)
1017 |
1018 |   Description   :  Perform a single character check for character ch
1019 |                    according to the fieldtype instance.
1020 |
1021 |   Return Values :  TRUE             - Character is valid
1022 |                    FALSE            - Character is invalid
1023 +--------------------------------------------------------------------------*/
1024 static bool
1025 Check_Char(FIELDTYPE *typ, int ch, TypeArgument *argp)
1026 {
1027   if (typ)
1028     {
1029       if (typ->status & _LINKED_TYPE)
1030         {
1031           assert(argp);
1032           return (
1033                    Check_Char(typ->left, ch, argp->left) ||
1034                    Check_Char(typ->right, ch, argp->right));
1035         }
1036       else
1037         {
1038           if (typ->ccheck)
1039             return typ->ccheck(ch, (void *)argp);
1040         }
1041     }
1042   return (!iscntrl(UChar(ch)) ? TRUE : FALSE);
1043 }
1044
1045 /*---------------------------------------------------------------------------
1046 |   Facility      :  libnform
1047 |   Function      :  static int Display_Or_Erase_Field(
1048 |                                           FIELD * field,
1049 |                                           bool bEraseFlag)
1050 |
1051 |   Description   :  Create a subwindow for the field and display the
1052 |                    buffer contents (apply justification if required)
1053 |                    or simply erase the field.
1054 |
1055 |   Return Values :  E_OK           - on success
1056 |                    E_SYSTEM_ERROR - some error (typical no memory)
1057 +--------------------------------------------------------------------------*/
1058 static int
1059 Display_Or_Erase_Field(FIELD *field, bool bEraseFlag)
1060 {
1061   WINDOW *win;
1062   WINDOW *fwin;
1063
1064   if (!field)
1065     return E_SYSTEM_ERROR;
1066
1067   fwin = Get_Form_Window(field->form);
1068   win = derwin(fwin,
1069                field->rows, field->cols, field->frow, field->fcol);
1070
1071   if (!win)
1072     return E_SYSTEM_ERROR;
1073   else
1074     {
1075       if (field->opts & O_VISIBLE)
1076         Set_Field_Window_Attributes(field, win);
1077       else
1078         wattrset(win, WINDOW_ATTRS(fwin));
1079       werase(win);
1080     }
1081
1082   if (!bEraseFlag)
1083     {
1084       if (field->opts & O_PUBLIC)
1085         {
1086           if (Justification_Allowed(field))
1087             Perform_Justification(field, win);
1088           else
1089             Buffer_To_Window(field, win);
1090         }
1091       field->status &= ~_NEWTOP;
1092     }
1093   wsyncup(win);
1094   delwin(win);
1095   return E_OK;
1096 }
1097
1098 /* Macros to preset the bEraseFlag */
1099 #define Display_Field(field) Display_Or_Erase_Field(field,FALSE)
1100 #define Erase_Field(field)   Display_Or_Erase_Field(field,TRUE)
1101
1102 /*---------------------------------------------------------------------------
1103 |   Facility      :  libnform
1104 |   Function      :  static int Synchronize_Field(FIELD * field)
1105 |
1106 |   Description   :  Synchronize the windows content with the value in
1107 |                    the buffer.
1108 |
1109 |   Return Values :  E_OK                - success
1110 |                    E_BAD_ARGUMENT      - invalid field pointer
1111 |                    E_SYSTEM_ERROR      - some severe basic error
1112 +--------------------------------------------------------------------------*/
1113 static int
1114 Synchronize_Field(FIELD *field)
1115 {
1116   FORM *form;
1117   int res = E_OK;
1118
1119   if (!field)
1120     return (E_BAD_ARGUMENT);
1121
1122   if (((form = field->form) != (FORM *)0)
1123       && Field_Really_Appears(field))
1124     {
1125       if (field == form->current)
1126         {
1127           form->currow = form->curcol = form->toprow = form->begincol = 0;
1128           werase(form->w);
1129
1130           if ((field->opts & O_PUBLIC) && Justification_Allowed(field))
1131             Undo_Justification(field, form->w);
1132           else
1133             Buffer_To_Window(field, form->w);
1134
1135           field->status |= _NEWTOP;
1136           res = _nc_Refresh_Current_Field(form);
1137         }
1138       else
1139         res = Display_Field(field);
1140     }
1141   field->status |= _CHANGED;
1142   return (res);
1143 }
1144
1145 /*---------------------------------------------------------------------------
1146 |   Facility      :  libnform
1147 |   Function      :  static int Synchronize_Linked_Fields(FIELD * field)
1148 |
1149 |   Description   :  Propagate the Synchronize_Field function to all linked
1150 |                    fields. The first error that occurs in the sequence
1151 |                    of updates is the return value.
1152 |
1153 |   Return Values :  E_OK                - success
1154 |                    E_BAD_ARGUMENT      - invalid field pointer
1155 |                    E_SYSTEM_ERROR      - some severe basic error
1156 +--------------------------------------------------------------------------*/
1157 static int
1158 Synchronize_Linked_Fields(FIELD *field)
1159 {
1160   FIELD *linked_field;
1161   int res = E_OK;
1162   int syncres;
1163
1164   if (!field)
1165     return (E_BAD_ARGUMENT);
1166
1167   if (!field->link)
1168     return (E_SYSTEM_ERROR);
1169
1170   for (linked_field = field->link;
1171        linked_field != field;
1172        linked_field = linked_field->link)
1173     {
1174       if (((syncres = Synchronize_Field(linked_field)) != E_OK) &&
1175           (res == E_OK))
1176         res = syncres;
1177     }
1178   return (res);
1179 }
1180
1181 /*---------------------------------------------------------------------------
1182 |   Facility      :  libnform
1183 |   Function      :  int _nc_Synchronize_Attributes(FIELD * field)
1184 |
1185 |   Description   :  If a fields visual attributes have changed, this
1186 |                    routine is called to propagate those changes to the
1187 |                    screen.
1188 |
1189 |   Return Values :  E_OK             - success
1190 |                    E_BAD_ARGUMENT   - invalid field pointer
1191 |                    E_SYSTEM_ERROR   - some severe basic error
1192 +--------------------------------------------------------------------------*/
1193 NCURSES_EXPORT(int)
1194 _nc_Synchronize_Attributes(FIELD *field)
1195 {
1196   FORM *form;
1197   int res = E_OK;
1198   WINDOW *formwin;
1199
1200   T((T_CALLED("_nc_Synchronize_Attributes(%p)"), field));
1201
1202   if (!field)
1203     returnCode(E_BAD_ARGUMENT);
1204
1205   CHECKPOS(field->form);
1206   if (((form = field->form) != (FORM *)0)
1207       && Field_Really_Appears(field))
1208     {
1209       if (form->current == field)
1210         {
1211           Synchronize_Buffer(form);
1212           Set_Field_Window_Attributes(field, form->w);
1213           werase(form->w);
1214           wmove(form->w, form->currow, form->curcol);
1215
1216           if (field->opts & O_PUBLIC)
1217             {
1218               if (Justification_Allowed(field))
1219                 Undo_Justification(field, form->w);
1220               else
1221                 Buffer_To_Window(field, form->w);
1222             }
1223           else
1224             {
1225               formwin = Get_Form_Window(form);
1226               copywin(form->w, formwin,
1227                       0, 0,
1228                       field->frow, field->fcol,
1229                       field->rows - 1, field->cols - 1, 0);
1230               wsyncup(formwin);
1231               Buffer_To_Window(field, form->w);
1232               field->status |= _NEWTOP;         /* fake refresh to paint all */
1233               _nc_Refresh_Current_Field(form);
1234             }
1235         }
1236       else
1237         {
1238           res = Display_Field(field);
1239         }
1240     }
1241   CHECKPOS(form);
1242   returnCode(res);
1243 }
1244
1245 /*---------------------------------------------------------------------------
1246 |   Facility      :  libnform
1247 |   Function      :  int _nc_Synchronize_Options(FIELD * field,
1248 |                                                Field_Options newopts)
1249 |
1250 |   Description   :  If a fields options have changed, this routine is
1251 |                    called to propagate these changes to the screen and
1252 |                    to really change the behavior of the field.
1253 |
1254 |   Return Values :  E_OK                - success
1255 |                    E_BAD_ARGUMENT      - invalid field pointer
1256 |                    E_CURRENT           - field is the current one
1257 |                    E_SYSTEM_ERROR      - some severe basic error
1258 +--------------------------------------------------------------------------*/
1259 NCURSES_EXPORT(int)
1260 _nc_Synchronize_Options(FIELD *field, Field_Options newopts)
1261 {
1262   Field_Options oldopts;
1263   Field_Options changed_opts;
1264   FORM *form;
1265   int res = E_OK;
1266
1267   T((T_CALLED("_nc_Synchronize_Options(%p,%#x)"), field, newopts));
1268
1269   if (!field)
1270     returnCode(E_BAD_ARGUMENT);
1271
1272   oldopts = field->opts;
1273   changed_opts = oldopts ^ newopts;
1274   field->opts = newopts;
1275   form = field->form;
1276
1277   if (form)
1278     {
1279       if (form->current == field)
1280         {
1281           field->opts = oldopts;
1282           returnCode(E_CURRENT);
1283         }
1284
1285       if (form->status & _POSTED)
1286         {
1287           if ((form->curpage == field->page))
1288             {
1289               if (changed_opts & O_VISIBLE)
1290                 {
1291                   if (newopts & O_VISIBLE)
1292                     res = Display_Field(field);
1293                   else
1294                     res = Erase_Field(field);
1295                 }
1296               else
1297                 {
1298                   if ((changed_opts & O_PUBLIC) &&
1299                       (newopts & O_VISIBLE))
1300                     res = Display_Field(field);
1301                 }
1302             }
1303         }
1304     }
1305
1306   if (changed_opts & O_STATIC)
1307     {
1308       bool single_line_field = Single_Line_Field(field);
1309       int res2 = E_OK;
1310
1311       if (newopts & O_STATIC)
1312         {
1313           /* the field becomes now static */
1314           field->status &= ~_MAY_GROW;
1315           /* if actually we have no hidden columns, justification may
1316              occur again */
1317           if (single_line_field &&
1318               (field->cols == field->dcols) &&
1319               (field->just != NO_JUSTIFICATION) &&
1320               Field_Really_Appears(field))
1321             {
1322               res2 = Display_Field(field);
1323             }
1324         }
1325       else
1326         {
1327           /* field is no longer static */
1328           if ((field->maxgrow == 0) ||
1329               (single_line_field && (field->dcols < field->maxgrow)) ||
1330               (!single_line_field && (field->drows < field->maxgrow)))
1331             {
1332               field->status |= _MAY_GROW;
1333               /* a field with justification now changes its behavior,
1334                  so we must redisplay it */
1335               if (single_line_field &&
1336                   (field->just != NO_JUSTIFICATION) &&
1337                   Field_Really_Appears(field))
1338                 {
1339                   res2 = Display_Field(field);
1340                 }
1341             }
1342         }
1343       if (res2 != E_OK)
1344         res = res2;
1345     }
1346
1347   returnCode(res);
1348 }
1349
1350 /*---------------------------------------------------------------------------
1351 |   Facility      :  libnform
1352 |   Function      :  int _nc_Set_Current_Field(FORM  * form,
1353 |                                              FIELD * newfield)
1354 |
1355 |   Description   :  Make the newfield the new current field.
1356 |
1357 |   Return Values :  E_OK              - success
1358 |                    E_BAD_ARGUMENT    - invalid form or field pointer
1359 |                    E_SYSTEM_ERROR    - some severe basic error
1360 |                    E_NOT_CONNECTED   - no fields are connected to the form
1361 +--------------------------------------------------------------------------*/
1362 NCURSES_EXPORT(int)
1363 _nc_Set_Current_Field(FORM *form, FIELD *newfield)
1364 {
1365   FIELD *field;
1366   WINDOW *new_window;
1367
1368   T((T_CALLED("_nc_Set_Current_Field(%p,%p)"), form, newfield));
1369
1370   if (!form || !newfield || !form->current || (newfield->form != form))
1371     returnCode(E_BAD_ARGUMENT);
1372
1373   if ((form->status & _IN_DRIVER))
1374     returnCode(E_BAD_STATE);
1375
1376   if (!(form->field))
1377     returnCode(E_NOT_CONNECTED);
1378
1379   field = form->current;
1380
1381   if ((field != newfield) ||
1382       !(form->status & _POSTED))
1383     {
1384       if ((form->w) &&
1385           (field->opts & O_VISIBLE) &&
1386           (field->form->curpage == field->page))
1387         {
1388           _nc_Refresh_Current_Field(form);
1389           if (field->opts & O_PUBLIC)
1390             {
1391               if (field->drows > field->rows)
1392                 {
1393                   if (form->toprow == 0)
1394                     field->status &= ~_NEWTOP;
1395                   else
1396                     field->status |= _NEWTOP;
1397                 }
1398               else
1399                 {
1400                   if (Justification_Allowed(field))
1401                     {
1402                       Window_To_Buffer(form->w, field);
1403                       werase(form->w);
1404                       Perform_Justification(field, form->w);
1405                       wsyncup(form->w);
1406                     }
1407                 }
1408             }
1409           delwin(form->w);
1410           form->w = (WINDOW *)0;
1411         }
1412
1413       field = newfield;
1414
1415       if (Has_Invisible_Parts(field))
1416         new_window = newpad(field->drows, field->dcols);
1417       else
1418         new_window = derwin(Get_Form_Window(form),
1419                             field->rows, field->cols, field->frow, field->fcol);
1420
1421       if (!new_window)
1422         returnCode(E_SYSTEM_ERROR);
1423
1424       form->current = field;
1425
1426       if (form->w)
1427         delwin(form->w);
1428       form->w = new_window;
1429
1430       form->status &= ~_WINDOW_MODIFIED;
1431       Set_Field_Window_Attributes(field, form->w);
1432
1433       if (Has_Invisible_Parts(field))
1434         {
1435           werase(form->w);
1436           Buffer_To_Window(field, form->w);
1437         }
1438       else
1439         {
1440           if (Justification_Allowed(field))
1441             {
1442               werase(form->w);
1443               Undo_Justification(field, form->w);
1444               wsyncup(form->w);
1445             }
1446         }
1447
1448       untouchwin(form->w);
1449     }
1450
1451   form->currow = form->curcol = form->toprow = form->begincol = 0;
1452   returnCode(E_OK);
1453 }
1454
1455 /*----------------------------------------------------------------------------
1456   Intra-Field Navigation routines
1457   --------------------------------------------------------------------------*/
1458
1459 /*---------------------------------------------------------------------------
1460 |   Facility      :  libnform
1461 |   Function      :  static int IFN_Next_Character(FORM * form)
1462 |
1463 |   Description   :  Move to the next character in the field. In a multi-line
1464 |                    field this wraps at the end of the line.
1465 |
1466 |   Return Values :  E_OK                - success
1467 |                    E_REQUEST_DENIED    - at the rightmost position
1468 +--------------------------------------------------------------------------*/
1469 static int
1470 IFN_Next_Character(FORM *form)
1471 {
1472   FIELD *field = form->current;
1473   int step = myWCWIDTH(form->w, form->currow, form->curcol);
1474
1475   T((T_CALLED("IFN_Next_Character(%p)"), form));
1476   if ((form->curcol += step) == field->dcols)
1477     {
1478       if ((++(form->currow)) == field->drows)
1479         {
1480 #if GROW_IF_NAVIGATE
1481           if (!Single_Line_Field(field) && Field_Grown(field, 1))
1482             {
1483               form->curcol = 0;
1484               returnCode(E_OK);
1485             }
1486 #endif
1487           form->currow--;
1488 #if GROW_IF_NAVIGATE
1489           if (Single_Line_Field(field) && Field_Grown(field, 1))
1490             returnCode(E_OK);
1491 #endif
1492           form->curcol -= step;
1493           returnCode(E_REQUEST_DENIED);
1494         }
1495       form->curcol = 0;
1496     }
1497   returnCode(E_OK);
1498 }
1499
1500 /*---------------------------------------------------------------------------
1501 |   Facility      :  libnform
1502 |   Function      :  static int IFN_Previous_Character(FORM * form)
1503 |
1504 |   Description   :  Move to the previous character in the field. In a
1505 |                    multi-line field this wraps and the beginning of the
1506 |                    line.
1507 |
1508 |   Return Values :  E_OK                - success
1509 |                    E_REQUEST_DENIED    - at the leftmost position
1510 +--------------------------------------------------------------------------*/
1511 static int
1512 IFN_Previous_Character(FORM *form)
1513 {
1514   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1515   int oldcol = form->curcol;
1516
1517   T((T_CALLED("IFN_Previous_Character(%p)"), form));
1518   if ((form->curcol -= amount) < 0)
1519     {
1520       if ((--(form->currow)) < 0)
1521         {
1522           form->currow++;
1523           form->curcol = oldcol;
1524           returnCode(E_REQUEST_DENIED);
1525         }
1526       form->curcol = form->current->dcols - 1;
1527     }
1528   returnCode(E_OK);
1529 }
1530
1531 /*---------------------------------------------------------------------------
1532 |   Facility      :  libnform
1533 |   Function      :  static int IFN_Next_Line(FORM * form)
1534 |
1535 |   Description   :  Move to the beginning of the next line in the field
1536 |
1537 |   Return Values :  E_OK                - success
1538 |                    E_REQUEST_DENIED    - at the last line
1539 +--------------------------------------------------------------------------*/
1540 static int
1541 IFN_Next_Line(FORM *form)
1542 {
1543   FIELD *field = form->current;
1544
1545   T((T_CALLED("IFN_Next_Line(%p)"), form));
1546   if ((++(form->currow)) == field->drows)
1547     {
1548 #if GROW_IF_NAVIGATE
1549       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1550         returnCode(E_OK);
1551 #endif
1552       form->currow--;
1553       returnCode(E_REQUEST_DENIED);
1554     }
1555   form->curcol = 0;
1556   returnCode(E_OK);
1557 }
1558
1559 /*---------------------------------------------------------------------------
1560 |   Facility      :  libnform
1561 |   Function      :  static int IFN_Previous_Line(FORM * form)
1562 |
1563 |   Description   :  Move to the beginning of the previous line in the field
1564 |
1565 |   Return Values :  E_OK                - success
1566 |                    E_REQUEST_DENIED    - at the first line
1567 +--------------------------------------------------------------------------*/
1568 static int
1569 IFN_Previous_Line(FORM *form)
1570 {
1571   T((T_CALLED("IFN_Previous_Line(%p)"), form));
1572   if ((--(form->currow)) < 0)
1573     {
1574       form->currow++;
1575       returnCode(E_REQUEST_DENIED);
1576     }
1577   form->curcol = 0;
1578   returnCode(E_OK);
1579 }
1580
1581 /*---------------------------------------------------------------------------
1582 |   Facility      :  libnform
1583 |   Function      :  static int IFN_Next_Word(FORM * form)
1584 |
1585 |   Description   :  Move to the beginning of the next word in the field.
1586 |
1587 |   Return Values :  E_OK             - success
1588 |                    E_REQUEST_DENIED - there is no next word
1589 +--------------------------------------------------------------------------*/
1590 static int
1591 IFN_Next_Word(FORM *form)
1592 {
1593   FIELD *field = form->current;
1594   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1595   FIELD_CELL *s;
1596   FIELD_CELL *t;
1597
1598   T((T_CALLED("IFN_Next_Word(%p)"), form));
1599
1600   /* We really need access to the data, so we have to synchronize */
1601   Synchronize_Buffer(form);
1602
1603   /* Go to the first whitespace after the current position (including
1604      current position). This is then the starting point to look for the
1605      next non-blank data */
1606   s = Get_First_Whitespace_Character(bp, Buffer_Length(field) -
1607                                      (int)(bp - field->buf));
1608
1609   /* Find the start of the next word */
1610   t = Get_Start_Of_Data(s, Buffer_Length(field) -
1611                         (int)(s - field->buf));
1612 #if !FRIENDLY_PREV_NEXT_WORD
1613   if (s == t)
1614     returnCode(E_REQUEST_DENIED);
1615   else
1616 #endif
1617     {
1618       Adjust_Cursor_Position(form, t);
1619       returnCode(E_OK);
1620     }
1621 }
1622
1623 /*---------------------------------------------------------------------------
1624 |   Facility      :  libnform
1625 |   Function      :  static int IFN_Previous_Word(FORM * form)
1626 |
1627 |   Description   :  Move to the beginning of the previous word in the field.
1628 |
1629 |   Return Values :  E_OK             - success
1630 |                    E_REQUEST_DENIED - there is no previous word
1631 +--------------------------------------------------------------------------*/
1632 static int
1633 IFN_Previous_Word(FORM *form)
1634 {
1635   FIELD *field = form->current;
1636   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1637   FIELD_CELL *s;
1638   FIELD_CELL *t;
1639   bool again = FALSE;
1640
1641   T((T_CALLED("IFN_Previous_Word(%p)"), form));
1642
1643   /* We really need access to the data, so we have to synchronize */
1644   Synchronize_Buffer(form);
1645
1646   s = After_End_Of_Data(field->buf, (int)(bp - field->buf));
1647   /* s points now right after the last non-blank in the buffer before bp.
1648      If bp was in a word, s equals bp. In this case we must find the last
1649      whitespace in the buffer before bp and repeat the game to really find
1650      the previous word! */
1651   if (s == bp)
1652     again = TRUE;
1653
1654   /* And next call now goes backward to look for the last whitespace
1655      before that, pointing right after this, so it points to the begin
1656      of the previous word.
1657    */
1658   t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1659 #if !FRIENDLY_PREV_NEXT_WORD
1660   if (s == t)
1661     returnCode(E_REQUEST_DENIED);
1662 #endif
1663   if (again)
1664     {
1665       /* and do it again, replacing bp by t */
1666       s = After_End_Of_Data(field->buf, (int)(t - field->buf));
1667       t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1668 #if !FRIENDLY_PREV_NEXT_WORD
1669       if (s == t)
1670         returnCode(E_REQUEST_DENIED);
1671 #endif
1672     }
1673   Adjust_Cursor_Position(form, t);
1674   returnCode(E_OK);
1675 }
1676
1677 /*---------------------------------------------------------------------------
1678 |   Facility      :  libnform
1679 |   Function      :  static int IFN_Beginning_Of_Field(FORM * form)
1680 |
1681 |   Description   :  Place the cursor at the first non-pad character in
1682 |                    the field.
1683 |
1684 |   Return Values :  E_OK             - success
1685 +--------------------------------------------------------------------------*/
1686 static int
1687 IFN_Beginning_Of_Field(FORM *form)
1688 {
1689   FIELD *field = form->current;
1690
1691   T((T_CALLED("IFN_Beginning_Of_Field(%p)"), form));
1692   Synchronize_Buffer(form);
1693   Adjust_Cursor_Position(form,
1694                          Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1695   returnCode(E_OK);
1696 }
1697
1698 /*---------------------------------------------------------------------------
1699 |   Facility      :  libnform
1700 |   Function      :  static int IFN_End_Of_Field(FORM * form)
1701 |
1702 |   Description   :  Place the cursor after the last non-pad character in
1703 |                    the field. If the field occupies the last position in
1704 |                    the buffer, the cursor is positioned on the last
1705 |                    character.
1706 |
1707 |   Return Values :  E_OK              - success
1708 +--------------------------------------------------------------------------*/
1709 static int
1710 IFN_End_Of_Field(FORM *form)
1711 {
1712   FIELD *field = form->current;
1713   FIELD_CELL *pos;
1714
1715   T((T_CALLED("IFN_End_Of_Field(%p)"), form));
1716   Synchronize_Buffer(form);
1717   pos = After_End_Of_Data(field->buf, Buffer_Length(field));
1718   if (pos == (field->buf + Buffer_Length(field)))
1719     pos--;
1720   Adjust_Cursor_Position(form, pos);
1721   returnCode(E_OK);
1722 }
1723
1724 /*---------------------------------------------------------------------------
1725 |   Facility      :  libnform
1726 |   Function      :  static int IFN_Beginning_Of_Line(FORM * form)
1727 |
1728 |   Description   :  Place the cursor on the first non-pad character in
1729 |                    the current line of the field.
1730 |
1731 |   Return Values :  E_OK         - success
1732 +--------------------------------------------------------------------------*/
1733 static int
1734 IFN_Beginning_Of_Line(FORM *form)
1735 {
1736   FIELD *field = form->current;
1737
1738   T((T_CALLED("IFN_Beginning_Of_Line(%p)"), form));
1739   Synchronize_Buffer(form);
1740   Adjust_Cursor_Position(form,
1741                          Get_Start_Of_Data(Address_Of_Current_Row_In_Buffer(form),
1742                                            field->dcols));
1743   returnCode(E_OK);
1744 }
1745
1746 /*---------------------------------------------------------------------------
1747 |   Facility      :  libnform
1748 |   Function      :  static int IFN_End_Of_Line(FORM * form)
1749 |
1750 |   Description   :  Place the cursor after the last non-pad character in the
1751 |                    current line of the field. If the field occupies the
1752 |                    last column in the line, the cursor is positioned on the
1753 |                    last character of the line.
1754 |
1755 |   Return Values :  E_OK        - success
1756 +--------------------------------------------------------------------------*/
1757 static int
1758 IFN_End_Of_Line(FORM *form)
1759 {
1760   FIELD *field = form->current;
1761   FIELD_CELL *pos;
1762   FIELD_CELL *bp;
1763
1764   T((T_CALLED("IFN_End_Of_Line(%p)"), form));
1765   Synchronize_Buffer(form);
1766   bp = Address_Of_Current_Row_In_Buffer(form);
1767   pos = After_End_Of_Data(bp, field->dcols);
1768   if (pos == (bp + field->dcols))
1769     pos--;
1770   Adjust_Cursor_Position(form, pos);
1771   returnCode(E_OK);
1772 }
1773
1774 /*---------------------------------------------------------------------------
1775 |   Facility      :  libnform
1776 |   Function      :  static int IFN_Left_Character(FORM * form)
1777 |
1778 |   Description   :  Move one character to the left in the current line.
1779 |                    This doesn't cycle.
1780 |
1781 |   Return Values :  E_OK             - success
1782 |                    E_REQUEST_DENIED - already in first column
1783 +--------------------------------------------------------------------------*/
1784 static int
1785 IFN_Left_Character(FORM *form)
1786 {
1787   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1788   int oldcol = form->curcol;
1789
1790   T((T_CALLED("IFN_Left_Character(%p)"), form));
1791   if ((form->curcol -= amount) < 0)
1792     {
1793       form->curcol = oldcol;
1794       returnCode(E_REQUEST_DENIED);
1795     }
1796   returnCode(E_OK);
1797 }
1798
1799 /*---------------------------------------------------------------------------
1800 |   Facility      :  libnform
1801 |   Function      :  static int IFN_Right_Character(FORM * form)
1802 |
1803 |   Description   :  Move one character to the right in the current line.
1804 |                    This doesn't cycle.
1805 |
1806 |   Return Values :  E_OK              - success
1807 |                    E_REQUEST_DENIED  - already in last column
1808 +--------------------------------------------------------------------------*/
1809 static int
1810 IFN_Right_Character(FORM *form)
1811 {
1812   int amount = myWCWIDTH(form->w, form->currow, form->curcol);
1813   int oldcol = form->curcol;
1814
1815   T((T_CALLED("IFN_Right_Character(%p)"), form));
1816   if ((form->curcol += amount) >= form->current->dcols)
1817     {
1818 #if GROW_IF_NAVIGATE
1819       FIELD *field = form->current;
1820
1821       if (Single_Line_Field(field) && Field_Grown(field, 1))
1822         returnCode(E_OK);
1823 #endif
1824       form->curcol = oldcol;
1825       returnCode(E_REQUEST_DENIED);
1826     }
1827   returnCode(E_OK);
1828 }
1829
1830 /*---------------------------------------------------------------------------
1831 |   Facility      :  libnform
1832 |   Function      :  static int IFN_Up_Character(FORM * form)
1833 |
1834 |   Description   :  Move one line up. This doesn't cycle through the lines
1835 |                    of the field.
1836 |
1837 |   Return Values :  E_OK              - success
1838 |                    E_REQUEST_DENIED  - already in last column
1839 +--------------------------------------------------------------------------*/
1840 static int
1841 IFN_Up_Character(FORM *form)
1842 {
1843   T((T_CALLED("IFN_Up_Character(%p)"), form));
1844   if ((--(form->currow)) < 0)
1845     {
1846       form->currow++;
1847       returnCode(E_REQUEST_DENIED);
1848     }
1849   returnCode(E_OK);
1850 }
1851
1852 /*---------------------------------------------------------------------------
1853 |   Facility      :  libnform
1854 |   Function      :  static int IFN_Down_Character(FORM * form)
1855 |
1856 |   Description   :  Move one line down. This doesn't cycle through the
1857 |                    lines of the field.
1858 |
1859 |   Return Values :  E_OK              - success
1860 |                    E_REQUEST_DENIED  - already in last column
1861 +--------------------------------------------------------------------------*/
1862 static int
1863 IFN_Down_Character(FORM *form)
1864 {
1865   FIELD *field = form->current;
1866
1867   T((T_CALLED("IFN_Down_Character(%p)"), form));
1868   if ((++(form->currow)) == field->drows)
1869     {
1870 #if GROW_IF_NAVIGATE
1871       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1872         returnCode(E_OK);
1873 #endif
1874       --(form->currow);
1875       returnCode(E_REQUEST_DENIED);
1876     }
1877   returnCode(E_OK);
1878 }
1879 /*----------------------------------------------------------------------------
1880   END of Intra-Field Navigation routines
1881   --------------------------------------------------------------------------*/
1882
1883 /*----------------------------------------------------------------------------
1884   Vertical scrolling helper routines
1885   --------------------------------------------------------------------------*/
1886
1887 /*---------------------------------------------------------------------------
1888 |   Facility      :  libnform
1889 |   Function      :  static int VSC_Generic(FORM *form, int nlines)
1890 |
1891 |   Description   :  Scroll multi-line field forward (nlines>0) or
1892 |                    backward (nlines<0) this many lines.
1893 |
1894 |   Return Values :  E_OK              - success
1895 |                    E_REQUEST_DENIED  - can't scroll
1896 +--------------------------------------------------------------------------*/
1897 static int
1898 VSC_Generic(FORM *form, int nlines)
1899 {
1900   FIELD *field = form->current;
1901   int res = E_REQUEST_DENIED;
1902   int rows_to_go = (nlines > 0 ? nlines : -nlines);
1903
1904   if (nlines > 0)
1905     {
1906       if ((rows_to_go + form->toprow) > (field->drows - field->rows))
1907         rows_to_go = (field->drows - field->rows - form->toprow);
1908
1909       if (rows_to_go > 0)
1910         {
1911           form->currow += rows_to_go;
1912           form->toprow += rows_to_go;
1913           res = E_OK;
1914         }
1915     }
1916   else
1917     {
1918       if (rows_to_go > form->toprow)
1919         rows_to_go = form->toprow;
1920
1921       if (rows_to_go > 0)
1922         {
1923           form->currow -= rows_to_go;
1924           form->toprow -= rows_to_go;
1925           res = E_OK;
1926         }
1927     }
1928   return (res);
1929 }
1930 /*----------------------------------------------------------------------------
1931   End of Vertical scrolling helper routines
1932   --------------------------------------------------------------------------*/
1933
1934 /*----------------------------------------------------------------------------
1935   Vertical scrolling routines
1936   --------------------------------------------------------------------------*/
1937
1938 /*---------------------------------------------------------------------------
1939 |   Facility      :  libnform
1940 |   Function      :  static int Vertical_Scrolling(
1941 |                                           int (* const fct) (FORM *),
1942 |                                           FORM * form)
1943 |
1944 |   Description   :  Performs the generic vertical scrolling routines.
1945 |                    This has to check for a multi-line field and to set
1946 |                    the _NEWTOP flag if scrolling really occurred.
1947 |
1948 |   Return Values :  Propagated error code from low-level driver calls
1949 +--------------------------------------------------------------------------*/
1950 static int
1951 Vertical_Scrolling(int (*const fct) (FORM *), FORM *form)
1952 {
1953   int res = E_REQUEST_DENIED;
1954
1955   if (!Single_Line_Field(form->current))
1956     {
1957       res = fct(form);
1958       if (res == E_OK)
1959         form->current->status |= _NEWTOP;
1960     }
1961   return (res);
1962 }
1963
1964 /*---------------------------------------------------------------------------
1965 |   Facility      :  libnform
1966 |   Function      :  static int VSC_Scroll_Line_Forward(FORM * form)
1967 |
1968 |   Description   :  Scroll multi-line field forward a line
1969 |
1970 |   Return Values :  E_OK                - success
1971 |                    E_REQUEST_DENIED    - no data ahead
1972 +--------------------------------------------------------------------------*/
1973 static int
1974 VSC_Scroll_Line_Forward(FORM *form)
1975 {
1976   T((T_CALLED("VSC_Scroll_Line_Forward(%p)"), form));
1977   returnCode(VSC_Generic(form, 1));
1978 }
1979
1980 /*---------------------------------------------------------------------------
1981 |   Facility      :  libnform
1982 |   Function      :  static int VSC_Scroll_Line_Backward(FORM * form)
1983 |
1984 |   Description   :  Scroll multi-line field backward a line
1985 |
1986 |   Return Values :  E_OK                - success
1987 |                    E_REQUEST_DENIED    - no data behind
1988 +--------------------------------------------------------------------------*/
1989 static int
1990 VSC_Scroll_Line_Backward(FORM *form)
1991 {
1992   T((T_CALLED("VSC_Scroll_Line_Backward(%p)"), form));
1993   returnCode(VSC_Generic(form, -1));
1994 }
1995
1996 /*---------------------------------------------------------------------------
1997 |   Facility      :  libnform
1998 |   Function      :  static int VSC_Scroll_Page_Forward(FORM * form)
1999 |
2000 |   Description   :  Scroll a multi-line field forward a page
2001 |
2002 |   Return Values :  E_OK              - success
2003 |                    E_REQUEST_DENIED  - no data ahead
2004 +--------------------------------------------------------------------------*/
2005 static int
2006 VSC_Scroll_Page_Forward(FORM *form)
2007 {
2008   T((T_CALLED("VSC_Scroll_Page_Forward(%p)"), form));
2009   returnCode(VSC_Generic(form, form->current->rows));
2010 }
2011
2012 /*---------------------------------------------------------------------------
2013 |   Facility      :  libnform
2014 |   Function      :  static int VSC_Scroll_Half_Page_Forward(FORM * form)
2015 |
2016 |   Description   :  Scroll a multi-line field forward half a page
2017 |
2018 |   Return Values :  E_OK              - success
2019 |                    E_REQUEST_DENIED  - no data ahead
2020 +--------------------------------------------------------------------------*/
2021 static int
2022 VSC_Scroll_Half_Page_Forward(FORM *form)
2023 {
2024   T((T_CALLED("VSC_Scroll_Half_Page_Forward(%p)"), form));
2025   returnCode(VSC_Generic(form, (form->current->rows + 1) / 2));
2026 }
2027
2028 /*---------------------------------------------------------------------------
2029 |   Facility      :  libnform
2030 |   Function      :  static int VSC_Scroll_Page_Backward(FORM * form)
2031 |
2032 |   Description   :  Scroll a multi-line field backward a page
2033 |
2034 |   Return Values :  E_OK              - success
2035 |                    E_REQUEST_DENIED  - no data behind
2036 +--------------------------------------------------------------------------*/
2037 static int
2038 VSC_Scroll_Page_Backward(FORM *form)
2039 {
2040   T((T_CALLED("VSC_Scroll_Page_Backward(%p)"), form));
2041   returnCode(VSC_Generic(form, -(form->current->rows)));
2042 }
2043
2044 /*---------------------------------------------------------------------------
2045 |   Facility      :  libnform
2046 |   Function      :  static int VSC_Scroll_Half_Page_Backward(FORM * form)
2047 |
2048 |   Description   :  Scroll a multi-line field backward half a page
2049 |
2050 |   Return Values :  E_OK              - success
2051 |                    E_REQUEST_DENIED  - no data behind
2052 +--------------------------------------------------------------------------*/
2053 static int
2054 VSC_Scroll_Half_Page_Backward(FORM *form)
2055 {
2056   T((T_CALLED("VSC_Scroll_Half_Page_Backward(%p)"), form));
2057   returnCode(VSC_Generic(form, -((form->current->rows + 1) / 2)));
2058 }
2059 /*----------------------------------------------------------------------------
2060   End of Vertical scrolling routines
2061   --------------------------------------------------------------------------*/
2062
2063 /*----------------------------------------------------------------------------
2064   Horizontal scrolling helper routines
2065   --------------------------------------------------------------------------*/
2066
2067 /*---------------------------------------------------------------------------
2068 |   Facility      :  libnform
2069 |   Function      :  static int HSC_Generic(FORM *form, int ncolumns)
2070 |
2071 |   Description   :  Scroll single-line field forward (ncolumns>0) or
2072 |                    backward (ncolumns<0) this many columns.
2073 |
2074 |   Return Values :  E_OK              - success
2075 |                    E_REQUEST_DENIED  - can't scroll
2076 +--------------------------------------------------------------------------*/
2077 static int
2078 HSC_Generic(FORM *form, int ncolumns)
2079 {
2080   FIELD *field = form->current;
2081   int res = E_REQUEST_DENIED;
2082   int cols_to_go = (ncolumns > 0 ? ncolumns : -ncolumns);
2083
2084   if (ncolumns > 0)
2085     {
2086       if ((cols_to_go + form->begincol) > (field->dcols - field->cols))
2087         cols_to_go = field->dcols - field->cols - form->begincol;
2088
2089       if (cols_to_go > 0)
2090         {
2091           form->curcol += cols_to_go;
2092           form->begincol += cols_to_go;
2093           res = E_OK;
2094         }
2095     }
2096   else
2097     {
2098       if (cols_to_go > form->begincol)
2099         cols_to_go = form->begincol;
2100
2101       if (cols_to_go > 0)
2102         {
2103           form->curcol -= cols_to_go;
2104           form->begincol -= cols_to_go;
2105           res = E_OK;
2106         }
2107     }
2108   return (res);
2109 }
2110 /*----------------------------------------------------------------------------
2111   End of Horizontal scrolling helper routines
2112   --------------------------------------------------------------------------*/
2113
2114 /*----------------------------------------------------------------------------
2115   Horizontal scrolling routines
2116   --------------------------------------------------------------------------*/
2117
2118 /*---------------------------------------------------------------------------
2119 |   Facility      :  libnform
2120 |   Function      :  static int Horizontal_Scrolling(
2121 |                                          int (* const fct) (FORM *),
2122 |                                          FORM * form)
2123 |
2124 |   Description   :  Performs the generic horizontal scrolling routines.
2125 |                    This has to check for a single-line field.
2126 |
2127 |   Return Values :  Propagated error code from low-level driver calls
2128 +--------------------------------------------------------------------------*/
2129 static int
2130 Horizontal_Scrolling(int (*const fct) (FORM *), FORM *form)
2131 {
2132   if (Single_Line_Field(form->current))
2133     return fct(form);
2134   else
2135     return (E_REQUEST_DENIED);
2136 }
2137
2138 /*---------------------------------------------------------------------------
2139 |   Facility      :  libnform
2140 |   Function      :  static int HSC_Scroll_Char_Forward(FORM * form)
2141 |
2142 |   Description   :  Scroll single-line field forward a character
2143 |
2144 |   Return Values :  E_OK                - success
2145 |                    E_REQUEST_DENIED    - no data ahead
2146 +--------------------------------------------------------------------------*/
2147 static int
2148 HSC_Scroll_Char_Forward(FORM *form)
2149 {
2150   T((T_CALLED("HSC_Scroll_Char_Forward(%p)"), form));
2151   returnCode(HSC_Generic(form, 1));
2152 }
2153
2154 /*---------------------------------------------------------------------------
2155 |   Facility      :  libnform
2156 |   Function      :  static int HSC_Scroll_Char_Backward(FORM * form)
2157 |
2158 |   Description   :  Scroll single-line field backward a character
2159 |
2160 |   Return Values :  E_OK                - success
2161 |                    E_REQUEST_DENIED    - no data behind
2162 +--------------------------------------------------------------------------*/
2163 static int
2164 HSC_Scroll_Char_Backward(FORM *form)
2165 {
2166   T((T_CALLED("HSC_Scroll_Char_Backward(%p)"), form));
2167   returnCode(HSC_Generic(form, -1));
2168 }
2169
2170 /*---------------------------------------------------------------------------
2171 |   Facility      :  libnform
2172 |   Function      :  static int HSC_Horizontal_Line_Forward(FORM* form)
2173 |
2174 |   Description   :  Scroll single-line field forward a line
2175 |
2176 |   Return Values :  E_OK                - success
2177 |                    E_REQUEST_DENIED    - no data ahead
2178 +--------------------------------------------------------------------------*/
2179 static int
2180 HSC_Horizontal_Line_Forward(FORM *form)
2181 {
2182   T((T_CALLED("HSC_Horizontal_Line_Forward(%p)"), form));
2183   returnCode(HSC_Generic(form, form->current->cols));
2184 }
2185
2186 /*---------------------------------------------------------------------------
2187 |   Facility      :  libnform
2188 |   Function      :  static int HSC_Horizontal_Half_Line_Forward(FORM* form)
2189 |
2190 |   Description   :  Scroll single-line field forward half a line
2191 |
2192 |   Return Values :  E_OK               - success
2193 |                    E_REQUEST_DENIED   - no data ahead
2194 +--------------------------------------------------------------------------*/
2195 static int
2196 HSC_Horizontal_Half_Line_Forward(FORM *form)
2197 {
2198   T((T_CALLED("HSC_Horizontal_Half_Line_Forward(%p)"), form));
2199   returnCode(HSC_Generic(form, (form->current->cols + 1) / 2));
2200 }
2201
2202 /*---------------------------------------------------------------------------
2203 |   Facility      :  libnform
2204 |   Function      :  static int HSC_Horizontal_Line_Backward(FORM* form)
2205 |
2206 |   Description   :  Scroll single-line field backward a line
2207 |
2208 |   Return Values :  E_OK                - success
2209 |                    E_REQUEST_DENIED    - no data behind
2210 +--------------------------------------------------------------------------*/
2211 static int
2212 HSC_Horizontal_Line_Backward(FORM *form)
2213 {
2214   T((T_CALLED("HSC_Horizontal_Line_Backward(%p)"), form));
2215   returnCode(HSC_Generic(form, -(form->current->cols)));
2216 }
2217
2218 /*---------------------------------------------------------------------------
2219 |   Facility      :  libnform
2220 |   Function      :  static int HSC_Horizontal_Half_Line_Backward(FORM* form)
2221 |
2222 |   Description   :  Scroll single-line field backward half a line
2223 |
2224 |   Return Values :  E_OK                - success
2225 |                    E_REQUEST_DENIED    - no data behind
2226 +--------------------------------------------------------------------------*/
2227 static int
2228 HSC_Horizontal_Half_Line_Backward(FORM *form)
2229 {
2230   T((T_CALLED("HSC_Horizontal_Half_Line_Backward(%p)"), form));
2231   returnCode(HSC_Generic(form, -((form->current->cols + 1) / 2)));
2232 }
2233
2234 /*----------------------------------------------------------------------------
2235   End of Horizontal scrolling routines
2236   --------------------------------------------------------------------------*/
2237
2238 /*----------------------------------------------------------------------------
2239   Helper routines for Field Editing
2240   --------------------------------------------------------------------------*/
2241
2242 /*---------------------------------------------------------------------------
2243 |   Facility      :  libnform
2244 |   Function      :  static bool Is_There_Room_For_A_Line(FORM * form)
2245 |
2246 |   Description   :  Check whether or not there is enough room in the
2247 |                    buffer to enter a whole line.
2248 |
2249 |   Return Values :  TRUE   - there is enough space
2250 |                    FALSE  - there is not enough space
2251 +--------------------------------------------------------------------------*/
2252 NCURSES_INLINE static bool
2253 Is_There_Room_For_A_Line(FORM *form)
2254 {
2255   FIELD *field = form->current;
2256   FIELD_CELL *begin_of_last_line, *s;
2257
2258   Synchronize_Buffer(form);
2259   begin_of_last_line = Address_Of_Row_In_Buffer(field, (field->drows - 1));
2260   s = After_End_Of_Data(begin_of_last_line, field->dcols);
2261   return ((s == begin_of_last_line) ? TRUE : FALSE);
2262 }
2263
2264 /*---------------------------------------------------------------------------
2265 |   Facility      :  libnform
2266 |   Function      :  static bool Is_There_Room_For_A_Char_In_Line(FORM * form)
2267 |
2268 |   Description   :  Checks whether or not there is room for a new character
2269 |                    in the current line.
2270 |
2271 |   Return Values :  TRUE    - there is room
2272 |                    FALSE   - there is not enough room (line full)
2273 +--------------------------------------------------------------------------*/
2274 NCURSES_INLINE static bool
2275 Is_There_Room_For_A_Char_In_Line(FORM *form)
2276 {
2277   int last_char_in_line;
2278
2279   wmove(form->w, form->currow, form->current->dcols - 1);
2280   last_char_in_line = (int)(winch(form->w) & A_CHARTEXT);
2281   wmove(form->w, form->currow, form->curcol);
2282   return (((last_char_in_line == form->current->pad) ||
2283            is_blank(last_char_in_line)) ? TRUE : FALSE);
2284 }
2285
2286 #define There_Is_No_Room_For_A_Char_In_Line(f) \
2287   !Is_There_Room_For_A_Char_In_Line(f)
2288
2289 /*---------------------------------------------------------------------------
2290 |   Facility      :  libnform
2291 |   Function      :  static int Insert_String(
2292 |                                             FORM * form,
2293 |                                             int row,
2294 |                                             char *txt,
2295 |                                             int  len )
2296 |
2297 |   Description   :  Insert the 'len' characters beginning at pointer 'txt'
2298 |                    into the 'row' of the 'form'. The insertion occurs
2299 |                    on the beginning of the row, all other characters are
2300 |                    moved to the right. After the text a pad character will
2301 |                    be inserted to separate the text from the rest. If
2302 |                    necessary the insertion moves characters on the next
2303 |                    line to make place for the requested insertion string.
2304 |
2305 |   Return Values :  E_OK              - success
2306 |                    E_REQUEST_DENIED  -
2307 |                    E_SYSTEM_ERROR    - system error
2308 +--------------------------------------------------------------------------*/
2309 static int
2310 Insert_String(FORM *form, int row, FIELD_CELL *txt, int len)
2311 {
2312   FIELD *field = form->current;
2313   FIELD_CELL *bp = Address_Of_Row_In_Buffer(field, row);
2314   int datalen = (int)(After_End_Of_Data(bp, field->dcols) - bp);
2315   int freelen = field->dcols - datalen;
2316   int requiredlen = len + 1;
2317   FIELD_CELL *split;
2318   int result = E_REQUEST_DENIED;
2319
2320   if (freelen >= requiredlen)
2321     {
2322       wmove(form->w, row, 0);
2323       myINSNSTR(form->w, txt, len);
2324       wmove(form->w, row, len);
2325       myINSNSTR(form->w, &myBLANK, 1);
2326       return E_OK;
2327     }
2328   else
2329     {
2330       /* we have to move characters on the next line. If we are on the
2331          last line this may work, if the field is growable */
2332       if ((row == (field->drows - 1)) && Growable(field))
2333         {
2334           if (!Field_Grown(field, 1))
2335             return (E_SYSTEM_ERROR);
2336           /* !!!Side-Effect : might be changed due to growth!!! */
2337           bp = Address_Of_Row_In_Buffer(field, row);
2338         }
2339
2340       if (row < (field->drows - 1))
2341         {
2342           split =
2343             After_Last_Whitespace_Character(bp,
2344                                             (int)(Get_Start_Of_Data(bp
2345                                                                     + field->dcols
2346                                                                     - requiredlen,
2347                                                                     requiredlen)
2348                                                   - bp));
2349           /* split points now to the first character of the portion of the
2350              line that must be moved to the next line */
2351           datalen = (int)(split - bp);  /* + freelen has to stay on this line   */
2352           freelen = field->dcols - (datalen + freelen);         /* for the next line */
2353
2354           if ((result = Insert_String(form, row + 1, split, freelen)) == E_OK)
2355             {
2356               wmove(form->w, row, datalen);
2357               wclrtoeol(form->w);
2358               wmove(form->w, row, 0);
2359               myINSNSTR(form->w, txt, len);
2360               wmove(form->w, row, len);
2361               myINSNSTR(form->w, &myBLANK, 1);
2362               return E_OK;
2363             }
2364         }
2365       return (result);
2366     }
2367 }
2368
2369 /*---------------------------------------------------------------------------
2370 |   Facility      :  libnform
2371 |   Function      :  static int Wrapping_Not_Necessary_Or_Wrapping_Ok(
2372 |                                             FORM * form)
2373 |
2374 |   Description   :  If a character has been entered into a field, it may
2375 |                    be that wrapping has to occur. This routine checks
2376 |                    whether or not wrapping is required and if so, performs
2377 |                    the wrapping.
2378 |
2379 |   Return Values :  E_OK              - no wrapping required or wrapping
2380 |                                        was successful
2381 |                    E_REQUEST_DENIED  -
2382 |                    E_SYSTEM_ERROR    - some system error
2383 +--------------------------------------------------------------------------*/
2384 static int
2385 Wrapping_Not_Necessary_Or_Wrapping_Ok(FORM *form)
2386 {
2387   FIELD *field = form->current;
2388   int result = E_REQUEST_DENIED;
2389   bool Last_Row = ((field->drows - 1) == form->currow);
2390
2391   if ((field->opts & O_WRAP) && /* wrapping wanted     */
2392       (!Single_Line_Field(field)) &&    /* must be multi-line  */
2393       (There_Is_No_Room_For_A_Char_In_Line(form)) &&    /* line is full        */
2394       (!Last_Row || Growable(field)))   /* there are more lines */
2395     {
2396       FIELD_CELL *bp;
2397       FIELD_CELL *split;
2398       int chars_to_be_wrapped;
2399       int chars_to_remain_on_line;
2400
2401       if (Last_Row)
2402         {
2403           /* the above logic already ensures, that in this case the field
2404              is growable */
2405           if (!Field_Grown(field, 1))
2406             return E_SYSTEM_ERROR;
2407         }
2408       bp = Address_Of_Current_Row_In_Buffer(form);
2409       Window_To_Buffer(form->w, field);
2410       split = After_Last_Whitespace_Character(bp, field->dcols);
2411       /* split points to the first character of the sequence to be brought
2412          on the next line */
2413       chars_to_remain_on_line = (int)(split - bp);
2414       chars_to_be_wrapped = field->dcols - chars_to_remain_on_line;
2415       if (chars_to_remain_on_line > 0)
2416         {
2417           if ((result = Insert_String(form, form->currow + 1, split,
2418                                       chars_to_be_wrapped)) == E_OK)
2419             {
2420               wmove(form->w, form->currow, chars_to_remain_on_line);
2421               wclrtoeol(form->w);
2422               if (form->curcol >= chars_to_remain_on_line)
2423                 {
2424                   form->currow++;
2425                   form->curcol -= chars_to_remain_on_line;
2426                 }
2427               return E_OK;
2428             }
2429         }
2430       else
2431         return E_OK;
2432       if (result != E_OK)
2433         {
2434           DeleteChar(form);
2435           Window_To_Buffer(form->w, field);
2436           result = E_REQUEST_DENIED;
2437         }
2438     }
2439   else
2440     result = E_OK;              /* wrapping was not necessary */
2441   return (result);
2442 }
2443
2444 /*----------------------------------------------------------------------------
2445   Field Editing routines
2446   --------------------------------------------------------------------------*/
2447
2448 /*---------------------------------------------------------------------------
2449 |   Facility      :  libnform
2450 |   Function      :  static int Field_Editing(
2451 |                                    int (* const fct) (FORM *),
2452 |                                    FORM * form)
2453 |
2454 |   Description   :  Generic routine for field editing requests. The driver
2455 |                    routines are only called for editable fields, the
2456 |                    _WINDOW_MODIFIED flag is set if editing occurred.
2457 |                    This is somewhat special due to the overload semantics
2458 |                    of the NEW_LINE and DEL_PREV requests.
2459 |
2460 |   Return Values :  Error code from low level drivers.
2461 +--------------------------------------------------------------------------*/
2462 static int
2463 Field_Editing(int (*const fct) (FORM *), FORM *form)
2464 {
2465   int res = E_REQUEST_DENIED;
2466
2467   /* We have to deal here with the specific case of the overloaded
2468      behavior of New_Line and Delete_Previous requests.
2469      They may end up in navigational requests if we are on the first
2470      character in a field. But navigation is also allowed on non-
2471      editable fields.
2472    */
2473   if ((fct == FE_Delete_Previous) &&
2474       (form->opts & O_BS_OVERLOAD) &&
2475       First_Position_In_Current_Field(form))
2476     {
2477       res = Inter_Field_Navigation(FN_Previous_Field, form);
2478     }
2479   else
2480     {
2481       if (fct == FE_New_Line)
2482         {
2483           if ((form->opts & O_NL_OVERLOAD) &&
2484               First_Position_In_Current_Field(form))
2485             {
2486               res = Inter_Field_Navigation(FN_Next_Field, form);
2487             }
2488           else
2489             /* FE_New_Line deals itself with the _WINDOW_MODIFIED flag */
2490             res = fct(form);
2491         }
2492       else
2493         {
2494           /* From now on, everything must be editable */
2495           if (form->current->opts & O_EDIT)
2496             {
2497               res = fct(form);
2498               if (res == E_OK)
2499                 form->status |= _WINDOW_MODIFIED;
2500             }
2501         }
2502     }
2503   return res;
2504 }
2505
2506 /*---------------------------------------------------------------------------
2507 |   Facility      :  libnform
2508 |   Function      :  static int FE_New_Line(FORM * form)
2509 |
2510 |   Description   :  Perform a new line request. This is rather complex
2511 |                    compared to other routines in this code due to the
2512 |                    rather difficult to understand description in the
2513 |                    manuals.
2514 |
2515 |   Return Values :  E_OK               - success
2516 |                    E_REQUEST_DENIED   - new line not allowed
2517 |                    E_SYSTEM_ERROR     - system error
2518 +--------------------------------------------------------------------------*/
2519 static int
2520 FE_New_Line(FORM *form)
2521 {
2522   FIELD *field = form->current;
2523   FIELD_CELL *bp, *t;
2524   bool Last_Row = ((field->drows - 1) == form->currow);
2525
2526   T((T_CALLED("FE_New_Line(%p)"), form));
2527   if (form->status & _OVLMODE)
2528     {
2529       if (Last_Row &&
2530           (!(Growable(field) && !Single_Line_Field(field))))
2531         {
2532           if (!(form->opts & O_NL_OVERLOAD))
2533             returnCode(E_REQUEST_DENIED);
2534           wmove(form->w, form->currow, form->curcol);
2535           wclrtoeol(form->w);
2536           /* we have to set this here, although it is also
2537              handled in the generic routine. The reason is,
2538              that FN_Next_Field may fail, but the form is
2539              definitively changed */
2540           form->status |= _WINDOW_MODIFIED;
2541           returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2542         }
2543       else
2544         {
2545           if (Last_Row && !Field_Grown(field, 1))
2546             {
2547               /* N.B.: due to the logic in the 'if', LastRow==TRUE
2548                  means here that the field is growable and not
2549                  a single-line field */
2550               returnCode(E_SYSTEM_ERROR);
2551             }
2552           wmove(form->w, form->currow, form->curcol);
2553           wclrtoeol(form->w);
2554           form->currow++;
2555           form->curcol = 0;
2556           form->status |= _WINDOW_MODIFIED;
2557           returnCode(E_OK);
2558         }
2559     }
2560   else
2561     {
2562       /* Insert Mode */
2563       if (Last_Row &&
2564           !(Growable(field) && !Single_Line_Field(field)))
2565         {
2566           if (!(form->opts & O_NL_OVERLOAD))
2567             returnCode(E_REQUEST_DENIED);
2568           returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2569         }
2570       else
2571         {
2572           bool May_Do_It = !Last_Row && Is_There_Room_For_A_Line(form);
2573
2574           if (!(May_Do_It || Growable(field)))
2575             returnCode(E_REQUEST_DENIED);
2576           if (!May_Do_It && !Field_Grown(field, 1))
2577             returnCode(E_SYSTEM_ERROR);
2578
2579           bp = Address_Of_Current_Position_In_Buffer(form);
2580           t = After_End_Of_Data(bp, field->dcols - form->curcol);
2581           wmove(form->w, form->currow, form->curcol);
2582           wclrtoeol(form->w);
2583           form->currow++;
2584           form->curcol = 0;
2585           wmove(form->w, form->currow, form->curcol);
2586           winsertln(form->w);
2587           myADDNSTR(form->w, bp, (int)(t - bp));
2588           form->status |= _WINDOW_MODIFIED;
2589           returnCode(E_OK);
2590         }
2591     }
2592 }
2593
2594 /*---------------------------------------------------------------------------
2595 |   Facility      :  libnform
2596 |   Function      :  static int FE_Insert_Character(FORM * form)
2597 |
2598 |   Description   :  Insert blank character at the cursor position
2599 |
2600 |   Return Values :  E_OK
2601 |                    E_REQUEST_DENIED
2602 +--------------------------------------------------------------------------*/
2603 static int
2604 FE_Insert_Character(FORM *form)
2605 {
2606   FIELD *field = form->current;
2607   int result = E_REQUEST_DENIED;
2608
2609   T((T_CALLED("FE_Insert_Character(%p)"), form));
2610   if (Check_Char(field->type, (int)C_BLANK, (TypeArgument *)(field->arg)))
2611     {
2612       bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
2613
2614       if (There_Is_Room ||
2615           ((Single_Line_Field(field) && Growable(field))))
2616         {
2617           if (!There_Is_Room && !Field_Grown(field, 1))
2618             result = E_SYSTEM_ERROR;
2619           else
2620             {
2621               winsch(form->w, (chtype)C_BLANK);
2622               result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form);
2623             }
2624         }
2625     }
2626   returnCode(result);
2627 }
2628
2629 /*---------------------------------------------------------------------------
2630 |   Facility      :  libnform
2631 |   Function      :  static int FE_Insert_Line(FORM * form)
2632 |
2633 |   Description   :  Insert a blank line at the cursor position
2634 |
2635 |   Return Values :  E_OK               - success
2636 |                    E_REQUEST_DENIED   - line can not be inserted
2637 +--------------------------------------------------------------------------*/
2638 static int
2639 FE_Insert_Line(FORM *form)
2640 {
2641   FIELD *field = form->current;
2642   int result = E_REQUEST_DENIED;
2643
2644   T((T_CALLED("FE_Insert_Line(%p)"), form));
2645   if (Check_Char(field->type, (int)C_BLANK, (TypeArgument *)(field->arg)))
2646     {
2647       bool Maybe_Done = (form->currow != (field->drows - 1)) &&
2648       Is_There_Room_For_A_Line(form);
2649
2650       if (!Single_Line_Field(field) &&
2651           (Maybe_Done || Growable(field)))
2652         {
2653           if (!Maybe_Done && !Field_Grown(field, 1))
2654             result = E_SYSTEM_ERROR;
2655           else
2656             {
2657               form->curcol = 0;
2658               winsertln(form->w);
2659               result = E_OK;
2660             }
2661         }
2662     }
2663   returnCode(result);
2664 }
2665
2666 /*---------------------------------------------------------------------------
2667 |   Facility      :  libnform
2668 |   Function      :  static int FE_Delete_Character(FORM * form)
2669 |
2670 |   Description   :  Delete character at the cursor position
2671 |
2672 |   Return Values :  E_OK    - success
2673 +--------------------------------------------------------------------------*/
2674 static int
2675 FE_Delete_Character(FORM *form)
2676 {
2677   T((T_CALLED("FE_Delete_Character(%p)"), form));
2678   DeleteChar(form);
2679   returnCode(E_OK);
2680 }
2681
2682 /*---------------------------------------------------------------------------
2683 |   Facility      :  libnform
2684 |   Function      :  static int FE_Delete_Previous(FORM * form)
2685 |
2686 |   Description   :  Delete character before cursor. Again this is a rather
2687 |                    difficult piece compared to others due to the overloading
2688 |                    semantics of backspace.
2689 |                    N.B.: The case of overloaded BS on first field position
2690 |                          is already handled in the generic routine.
2691 |
2692 |   Return Values :  E_OK                - success
2693 |                    E_REQUEST_DENIED    - Character can't be deleted
2694 +--------------------------------------------------------------------------*/
2695 static int
2696 FE_Delete_Previous(FORM *form)
2697 {
2698   FIELD *field = form->current;
2699
2700   T((T_CALLED("FE_Delete_Previous(%p)"), form));
2701   if (First_Position_In_Current_Field(form))
2702     returnCode(E_REQUEST_DENIED);
2703
2704   if ((--(form->curcol)) < 0)
2705     {
2706       FIELD_CELL *this_line, *prev_line, *prev_end, *this_end;
2707       int this_row = form->currow;
2708
2709       form->curcol++;
2710       if (form->status & _OVLMODE)
2711         returnCode(E_REQUEST_DENIED);
2712
2713       prev_line = Address_Of_Row_In_Buffer(field, (form->currow - 1));
2714       this_line = Address_Of_Row_In_Buffer(field, (form->currow));
2715       Synchronize_Buffer(form);
2716       prev_end = After_End_Of_Data(prev_line, field->dcols);
2717       this_end = After_End_Of_Data(this_line, field->dcols);
2718       if ((int)(this_end - this_line) >
2719           (field->cols - (int)(prev_end - prev_line)))
2720         returnCode(E_REQUEST_DENIED);
2721       wmove(form->w, form->currow, form->curcol);
2722       wdeleteln(form->w);
2723       Adjust_Cursor_Position(form, prev_end);
2724       /*
2725        * If we did not really move to the previous line, help the user a
2726        * little.  It is however a little inconsistent.  Normally, when
2727        * backspacing around the point where text wraps to a new line in a
2728        * multi-line form, we absorb one keystroke for the wrapping point.  That
2729        * is consistent with SVr4 forms.  However, SVr4 does not allow typing
2730        * into the last column of the field, and requires the user to enter a
2731        * newline to move to the next line.  Therefore it can consistently eat
2732        * that keystroke.  Since ncurses allows the last column, it wraps
2733        * automatically (given the proper options).  But we cannot eat the
2734        * keystroke to back over the wrapping point, since that would put the
2735        * cursor past the end of the form field.  In this case, just delete the
2736        * character at the end of the field.
2737        */
2738       if (form->currow == this_row && this_row > 0)
2739         {
2740           form->currow -= 1;
2741           form->curcol = field->dcols - 1;
2742           DeleteChar(form);
2743         }
2744       else
2745         {
2746           wmove(form->w, form->currow, form->curcol);
2747           myADDNSTR(form->w, this_line, (int)(this_end - this_line));
2748         }
2749     }
2750   else
2751     {
2752       DeleteChar(form);
2753     }
2754   returnCode(E_OK);
2755 }
2756
2757 /*---------------------------------------------------------------------------
2758 |   Facility      :  libnform
2759 |   Function      :  static int FE_Delete_Line(FORM * form)
2760 |
2761 |   Description   :  Delete line at cursor position.
2762 |
2763 |   Return Values :  E_OK  - success
2764 +--------------------------------------------------------------------------*/
2765 static int
2766 FE_Delete_Line(FORM *form)
2767 {
2768   T((T_CALLED("FE_Delete_Line(%p)"), form));
2769   form->curcol = 0;
2770   wdeleteln(form->w);
2771   returnCode(E_OK);
2772 }
2773
2774 /*---------------------------------------------------------------------------
2775 |   Facility      :  libnform
2776 |   Function      :  static int FE_Delete_Word(FORM * form)
2777 |
2778 |   Description   :  Delete word at cursor position
2779 |
2780 |   Return Values :  E_OK               - success
2781 |                    E_REQUEST_DENIED   - failure
2782 +--------------------------------------------------------------------------*/
2783 static int
2784 FE_Delete_Word(FORM *form)
2785 {
2786   FIELD *field = form->current;
2787   FIELD_CELL *bp = Address_Of_Current_Row_In_Buffer(form);
2788   FIELD_CELL *ep = bp + field->dcols;
2789   FIELD_CELL *cp = bp + form->curcol;
2790   FIELD_CELL *s;
2791
2792   T((T_CALLED("FE_Delete_Word(%p)"), form));
2793   Synchronize_Buffer(form);
2794   if (ISBLANK(*cp))
2795     returnCode(E_REQUEST_DENIED);       /* not in word */
2796
2797   /* move cursor to begin of word and erase to end of screen-line */
2798   Adjust_Cursor_Position(form,
2799                          After_Last_Whitespace_Character(bp, form->curcol));
2800   wmove(form->w, form->currow, form->curcol);
2801   wclrtoeol(form->w);
2802
2803   /* skip over word in buffer */
2804   s = Get_First_Whitespace_Character(cp, (int)(ep - cp));
2805   /* to begin of next word    */
2806   s = Get_Start_Of_Data(s, (int)(ep - s));
2807   if ((s != cp) && !ISBLANK(*s))
2808     {
2809       /* copy remaining line to window */
2810       myADDNSTR(form->w, s, (int)(s - After_End_Of_Data(s, (int)(ep - s))));
2811     }
2812   returnCode(E_OK);
2813 }
2814
2815 /*---------------------------------------------------------------------------
2816 |   Facility      :  libnform
2817 |   Function      :  static int FE_Clear_To_End_Of_Line(FORM * form)
2818 |
2819 |   Description   :  Clear to end of current line.
2820 |
2821 |   Return Values :  E_OK   - success
2822 +--------------------------------------------------------------------------*/
2823 static int
2824 FE_Clear_To_End_Of_Line(FORM *form)
2825 {
2826   T((T_CALLED("FE_Clear_To_End_Of_Line(%p)"), form));
2827   wmove(form->w, form->currow, form->curcol);
2828   wclrtoeol(form->w);
2829   returnCode(E_OK);
2830 }
2831
2832 /*---------------------------------------------------------------------------
2833 |   Facility      :  libnform
2834 |   Function      :  static int FE_Clear_To_End_Of_Field(FORM * form)
2835 |
2836 |   Description   :  Clear to end of field.
2837 |
2838 |   Return Values :  E_OK   - success
2839 +--------------------------------------------------------------------------*/
2840 static int
2841 FE_Clear_To_End_Of_Field(FORM *form)
2842 {
2843   T((T_CALLED("FE_Clear_To_End_Of_Field(%p)"), form));
2844   wmove(form->w, form->currow, form->curcol);
2845   wclrtobot(form->w);
2846   returnCode(E_OK);
2847 }
2848
2849 /*---------------------------------------------------------------------------
2850 |   Facility      :  libnform
2851 |   Function      :  static int FE_Clear_Field(FORM * form)
2852 |
2853 |   Description   :  Clear entire field.
2854 |
2855 |   Return Values :  E_OK   - success
2856 +--------------------------------------------------------------------------*/
2857 static int
2858 FE_Clear_Field(FORM *form)
2859 {
2860   T((T_CALLED("FE_Clear_Field(%p)"), form));
2861   form->currow = form->curcol = 0;
2862   werase(form->w);
2863   returnCode(E_OK);
2864 }
2865 /*----------------------------------------------------------------------------
2866   END of Field Editing routines
2867   --------------------------------------------------------------------------*/
2868
2869 /*----------------------------------------------------------------------------
2870   Edit Mode routines
2871   --------------------------------------------------------------------------*/
2872
2873 /*---------------------------------------------------------------------------
2874 |   Facility      :  libnform
2875 |   Function      :  static int EM_Overlay_Mode(FORM * form)
2876 |
2877 |   Description   :  Switch to overlay mode.
2878 |
2879 |   Return Values :  E_OK   - success
2880 +--------------------------------------------------------------------------*/
2881 static int
2882 EM_Overlay_Mode(FORM *form)
2883 {
2884   T((T_CALLED("EM_Overlay_Mode(%p)"), form));
2885   form->status |= _OVLMODE;
2886   returnCode(E_OK);
2887 }
2888
2889 /*---------------------------------------------------------------------------
2890 |   Facility      :  libnform
2891 |   Function      :  static int EM_Insert_Mode(FORM * form)
2892 |
2893 |   Description   :  Switch to insert mode
2894 |
2895 |   Return Values :  E_OK   - success
2896 +--------------------------------------------------------------------------*/
2897 static int
2898 EM_Insert_Mode(FORM *form)
2899 {
2900   T((T_CALLED("EM_Insert_Mode(%p)"), form));
2901   form->status &= ~_OVLMODE;
2902   returnCode(E_OK);
2903 }
2904
2905 /*----------------------------------------------------------------------------
2906   END of Edit Mode routines
2907   --------------------------------------------------------------------------*/
2908
2909 /*----------------------------------------------------------------------------
2910   Helper routines for Choice Requests
2911   --------------------------------------------------------------------------*/
2912
2913 /*---------------------------------------------------------------------------
2914 |   Facility      :  libnform
2915 |   Function      :  static bool Next_Choice(
2916 |                                            FIELDTYPE * typ,
2917 |                                            FIELD * field,
2918 |                                            TypeArgument *argp)
2919 |
2920 |   Description   :  Get the next field choice. For linked types this is
2921 |                    done recursively.
2922 |
2923 |   Return Values :  TRUE    - next choice successfully retrieved
2924 |                    FALSE   - couldn't retrieve next choice
2925 +--------------------------------------------------------------------------*/
2926 static bool
2927 Next_Choice(FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
2928 {
2929   if (!typ || !(typ->status & _HAS_CHOICE))
2930     return FALSE;
2931
2932   if (typ->status & _LINKED_TYPE)
2933     {
2934       assert(argp);
2935       return (
2936                Next_Choice(typ->left, field, argp->left) ||
2937                Next_Choice(typ->right, field, argp->right));
2938     }
2939   else
2940     {
2941       assert(typ->next);
2942       return typ->next(field, (void *)argp);
2943     }
2944 }
2945
2946 /*---------------------------------------------------------------------------
2947 |   Facility      :  libnform
2948 |   Function      :  static bool Previous_Choice(
2949 |                                                FIELDTYPE * typ,
2950 |                                                FIELD * field,
2951 |                                                TypeArgument *argp)
2952 |
2953 |   Description   :  Get the previous field choice. For linked types this
2954 |                    is done recursively.
2955 |
2956 |   Return Values :  TRUE    - previous choice successfully retrieved
2957 |                    FALSE   - couldn't retrieve previous choice
2958 +--------------------------------------------------------------------------*/
2959 static bool
2960 Previous_Choice(FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
2961 {
2962   if (!typ || !(typ->status & _HAS_CHOICE))
2963     return FALSE;
2964
2965   if (typ->status & _LINKED_TYPE)
2966     {
2967       assert(argp);
2968       return (
2969                Previous_Choice(typ->left, field, argp->left) ||
2970                Previous_Choice(typ->right, field, argp->right));
2971     }
2972   else
2973     {
2974       assert(typ->prev);
2975       return typ->prev(field, (void *)argp);
2976     }
2977 }
2978 /*----------------------------------------------------------------------------
2979   End of Helper routines for Choice Requests
2980   --------------------------------------------------------------------------*/
2981
2982 /*----------------------------------------------------------------------------
2983   Routines for Choice Requests
2984   --------------------------------------------------------------------------*/
2985
2986 /*---------------------------------------------------------------------------
2987 |   Facility      :  libnform
2988 |   Function      :  static int CR_Next_Choice(FORM * form)
2989 |
2990 |   Description   :  Get the next field choice.
2991 |
2992 |   Return Values :  E_OK              - success
2993 |                    E_REQUEST_DENIED  - next choice couldn't be retrieved
2994 +--------------------------------------------------------------------------*/
2995 static int
2996 CR_Next_Choice(FORM *form)
2997 {
2998   FIELD *field = form->current;
2999
3000   T((T_CALLED("CR_Next_Choice(%p)"), form));
3001   Synchronize_Buffer(form);
3002   returnCode((Next_Choice(field->type, field, (TypeArgument *)(field->arg)))
3003              ? E_OK
3004              : E_REQUEST_DENIED);
3005 }
3006
3007 /*---------------------------------------------------------------------------
3008 |   Facility      :  libnform
3009 |   Function      :  static int CR_Previous_Choice(FORM * form)
3010 |
3011 |   Description   :  Get the previous field choice.
3012 |
3013 |   Return Values :  E_OK              - success
3014 |                    E_REQUEST_DENIED  - prev. choice couldn't be retrieved
3015 +--------------------------------------------------------------------------*/
3016 static int
3017 CR_Previous_Choice(FORM *form)
3018 {
3019   FIELD *field = form->current;
3020
3021   T((T_CALLED("CR_Previous_Choice(%p)"), form));
3022   Synchronize_Buffer(form);
3023   returnCode((Previous_Choice(field->type, field, (TypeArgument *)(field->arg)))
3024              ? E_OK
3025              : E_REQUEST_DENIED);
3026 }
3027 /*----------------------------------------------------------------------------
3028   End of Routines for Choice Requests
3029   --------------------------------------------------------------------------*/
3030
3031 /*----------------------------------------------------------------------------
3032   Helper routines for Field Validations.
3033   --------------------------------------------------------------------------*/
3034
3035 /*---------------------------------------------------------------------------
3036 |   Facility      :  libnform
3037 |   Function      :  static bool Check_Field(
3038 |                                            FIELDTYPE * typ,
3039 |                                            FIELD * field,
3040 |                                            TypeArgument * argp)
3041 |
3042 |   Description   :  Check the field according to its fieldtype and its
3043 |                    actual arguments. For linked fieldtypes this is done
3044 |                    recursively.
3045 |
3046 |   Return Values :  TRUE       - field is valid
3047 |                    FALSE      - field is invalid.
3048 +--------------------------------------------------------------------------*/
3049 static bool
3050 Check_Field(FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3051 {
3052   if (typ)
3053     {
3054       if (field->opts & O_NULLOK)
3055         {
3056           FIELD_CELL *bp = field->buf;
3057
3058           assert(bp);
3059           while (ISBLANK(*bp))
3060             {
3061               bp++;
3062             }
3063           if (CharOf(*bp) == 0)
3064             return TRUE;
3065         }
3066
3067       if (typ->status & _LINKED_TYPE)
3068         {
3069           assert(argp);
3070           return (
3071                    Check_Field(typ->left, field, argp->left) ||
3072                    Check_Field(typ->right, field, argp->right));
3073         }
3074       else
3075         {
3076           if (typ->fcheck)
3077             return typ->fcheck(field, (void *)argp);
3078         }
3079     }
3080   return TRUE;
3081 }
3082
3083 /*---------------------------------------------------------------------------
3084 |   Facility      :  libnform
3085 |   Function      :  bool _nc_Internal_Validation(FORM * form )
3086 |
3087 |   Description   :  Validate the current field of the form.
3088 |
3089 |   Return Values :  TRUE  - field is valid
3090 |                    FALSE - field is invalid
3091 +--------------------------------------------------------------------------*/
3092 NCURSES_EXPORT(bool)
3093 _nc_Internal_Validation(FORM *form)
3094 {
3095   FIELD *field;
3096
3097   field = form->current;
3098
3099   Synchronize_Buffer(form);
3100   if ((form->status & _FCHECK_REQUIRED) ||
3101       (!(field->opts & O_PASSOK)))
3102     {
3103       if (!Check_Field(field->type, field, (TypeArgument *)(field->arg)))
3104         return FALSE;
3105       form->status &= ~_FCHECK_REQUIRED;
3106       field->status |= _CHANGED;
3107       Synchronize_Linked_Fields(field);
3108     }
3109   return TRUE;
3110 }
3111 /*----------------------------------------------------------------------------
3112   End of Helper routines for Field Validations.
3113   --------------------------------------------------------------------------*/
3114
3115 /*----------------------------------------------------------------------------
3116   Routines for Field Validation.
3117   --------------------------------------------------------------------------*/
3118
3119 /*---------------------------------------------------------------------------
3120 |   Facility      :  libnform
3121 |   Function      :  static int FV_Validation(FORM * form)
3122 |
3123 |   Description   :  Validate the current field of the form.
3124 |
3125 |   Return Values :  E_OK             - field valid
3126 |                    E_INVALID_FIELD  - field not valid
3127 +--------------------------------------------------------------------------*/
3128 static int
3129 FV_Validation(FORM *form)
3130 {
3131   T((T_CALLED("FV_Validation(%p)"), form));
3132   if (_nc_Internal_Validation(form))
3133     returnCode(E_OK);
3134   else
3135     returnCode(E_INVALID_FIELD);
3136 }
3137 /*----------------------------------------------------------------------------
3138   End of routines for Field Validation.
3139   --------------------------------------------------------------------------*/
3140
3141 /*----------------------------------------------------------------------------
3142   Helper routines for Inter-Field Navigation
3143   --------------------------------------------------------------------------*/
3144
3145 /*---------------------------------------------------------------------------
3146 |   Facility      :  libnform
3147 |   Function      :  static FIELD *Next_Field_On_Page(FIELD * field)
3148 |
3149 |   Description   :  Get the next field after the given field on the current
3150 |                    page. The order of fields is the one defined by the
3151 |                    fields array. Only visible and active fields are
3152 |                    counted.
3153 |
3154 |   Return Values :  Pointer to the next field.
3155 +--------------------------------------------------------------------------*/
3156 NCURSES_INLINE static FIELD *
3157 Next_Field_On_Page(FIELD *field)
3158 {
3159   FORM *form = field->form;
3160   FIELD **field_on_page = &form->field[field->index];
3161   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3162   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3163
3164   do
3165     {
3166       field_on_page =
3167         (field_on_page == last_on_page) ? first_on_page : field_on_page + 1;
3168       if (Field_Is_Selectable(*field_on_page))
3169         break;
3170     }
3171   while (field != (*field_on_page));
3172   return (*field_on_page);
3173 }
3174
3175 /*---------------------------------------------------------------------------
3176 |   Facility      :  libnform
3177 |   Function      :  FIELD* _nc_First_Active_Field(FORM * form)
3178 |
3179 |   Description   :  Get the first active field on the current page,
3180 |                    if there are such. If there are none, get the first
3181 |                    visible field on the page. If there are also none,
3182 |                    we return the first field on page and hope the best.
3183 |
3184 |   Return Values :  Pointer to calculated field.
3185 +--------------------------------------------------------------------------*/
3186 NCURSES_EXPORT(FIELD *)
3187 _nc_First_Active_Field(FORM *form)
3188 {
3189   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3190   FIELD *proposed = Next_Field_On_Page(*last_on_page);
3191
3192   if (proposed == *last_on_page)
3193     {
3194       /* there might be the special situation, where there is no
3195          active and visible field on the current page. We then select
3196          the first visible field on this readonly page
3197        */
3198       if (Field_Is_Not_Selectable(proposed))
3199         {
3200           FIELD **field = &form->field[proposed->index];
3201           FIELD **first = &form->field[form->page[form->curpage].pmin];
3202
3203           do
3204             {
3205               field = (field == last_on_page) ? first : field + 1;
3206               if (((*field)->opts & O_VISIBLE))
3207                 break;
3208             }
3209           while (proposed != (*field));
3210
3211           proposed = *field;
3212
3213           if ((proposed == *last_on_page) && !(proposed->opts & O_VISIBLE))
3214             {
3215               /* This means, there is also no visible field on the page.
3216                  So we propose the first one and hope the very best...
3217                  Some very clever user has designed a readonly and invisible
3218                  page on this form.
3219                */
3220               proposed = *first;
3221             }
3222         }
3223     }
3224   return (proposed);
3225 }
3226
3227 /*---------------------------------------------------------------------------
3228 |   Facility      :  libnform
3229 |   Function      :  static FIELD *Previous_Field_On_Page(FIELD * field)
3230 |
3231 |   Description   :  Get the previous field before the given field on the
3232 |                    current page. The order of fields is the one defined by
3233 |                    the fields array. Only visible and active fields are
3234 |                    counted.
3235 |
3236 |   Return Values :  Pointer to the previous field.
3237 +--------------------------------------------------------------------------*/
3238 NCURSES_INLINE static FIELD *
3239 Previous_Field_On_Page(FIELD *field)
3240 {
3241   FORM *form = field->form;
3242   FIELD **field_on_page = &form->field[field->index];
3243   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3244   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3245
3246   do
3247     {
3248       field_on_page =
3249         (field_on_page == first_on_page) ? last_on_page : field_on_page - 1;
3250       if (Field_Is_Selectable(*field_on_page))
3251         break;
3252     }
3253   while (field != (*field_on_page));
3254
3255   return (*field_on_page);
3256 }
3257
3258 /*---------------------------------------------------------------------------
3259 |   Facility      :  libnform
3260 |   Function      :  static FIELD *Sorted_Next_Field(FIELD * field)
3261 |
3262 |   Description   :  Get the next field after the given field on the current
3263 |                    page. The order of fields is the one defined by the
3264 |                    (row,column) geometry, rows are major.
3265 |
3266 |   Return Values :  Pointer to the next field.
3267 +--------------------------------------------------------------------------*/
3268 NCURSES_INLINE static FIELD *
3269 Sorted_Next_Field(FIELD *field)
3270 {
3271   FIELD *field_on_page = field;
3272
3273   do
3274     {
3275       field_on_page = field_on_page->snext;
3276       if (Field_Is_Selectable(field_on_page))
3277         break;
3278     }
3279   while (field_on_page != field);
3280
3281   return (field_on_page);
3282 }
3283
3284 /*---------------------------------------------------------------------------
3285 |   Facility      :  libnform
3286 |   Function      :  static FIELD *Sorted_Previous_Field(FIELD * field)
3287 |
3288 |   Description   :  Get the previous field before the given field on the
3289 |                    current page. The order of fields is the one defined
3290 |                    by the (row,column) geometry, rows are major.
3291 |
3292 |   Return Values :  Pointer to the previous field.
3293 +--------------------------------------------------------------------------*/
3294 NCURSES_INLINE static FIELD *
3295 Sorted_Previous_Field(FIELD *field)
3296 {
3297   FIELD *field_on_page = field;
3298
3299   do
3300     {
3301       field_on_page = field_on_page->sprev;
3302       if (Field_Is_Selectable(field_on_page))
3303         break;
3304     }
3305   while (field_on_page != field);
3306
3307   return (field_on_page);
3308 }
3309
3310 /*---------------------------------------------------------------------------
3311 |   Facility      :  libnform
3312 |   Function      :  static FIELD *Left_Neighbor_Field(FIELD * field)
3313 |
3314 |   Description   :  Get the left neighbor of the field on the same line
3315 |                    and the same page. Cycles through the line.
3316 |
3317 |   Return Values :  Pointer to left neighbor field.
3318 +--------------------------------------------------------------------------*/
3319 NCURSES_INLINE static FIELD *
3320 Left_Neighbor_Field(FIELD *field)
3321 {
3322   FIELD *field_on_page = field;
3323
3324   /* For a field that has really a left neighbor, the while clause
3325      immediately fails and the loop is left, positioned at the right
3326      neighbor. Otherwise we cycle backwards through the sorted field list
3327      until we enter the same line (from the right end).
3328    */
3329   do
3330     {
3331       field_on_page = Sorted_Previous_Field(field_on_page);
3332     }
3333   while (field_on_page->frow != field->frow);
3334
3335   return (field_on_page);
3336 }
3337
3338 /*---------------------------------------------------------------------------
3339 |   Facility      :  libnform
3340 |   Function      :  static FIELD *Right_Neighbor_Field(FIELD * field)
3341 |
3342 |   Description   :  Get the right neighbor of the field on the same line
3343 |                    and the same page.
3344 |
3345 |   Return Values :  Pointer to right neighbor field.
3346 +--------------------------------------------------------------------------*/
3347 NCURSES_INLINE static FIELD *
3348 Right_Neighbor_Field(FIELD *field)
3349 {
3350   FIELD *field_on_page = field;
3351
3352   /* See the comments on Left_Neighbor_Field to understand how it works */
3353   do
3354     {
3355       field_on_page = Sorted_Next_Field(field_on_page);
3356     }
3357   while (field_on_page->frow != field->frow);
3358
3359   return (field_on_page);
3360 }
3361
3362 /*---------------------------------------------------------------------------
3363 |   Facility      :  libnform
3364 |   Function      :  static FIELD *Upper_Neighbor_Field(FIELD * field)
3365 |
3366 |   Description   :  Because of the row-major nature of sorting the fields,
3367 |                    it is more difficult to define whats the upper neighbor
3368 |                    field really means. We define that it must be on a
3369 |                    'previous' line (cyclic order!) and is the rightmost
3370 |                    field laying on the left side of the given field. If
3371 |                    this set is empty, we take the first field on the line.
3372 |
3373 |   Return Values :  Pointer to the upper neighbor field.
3374 +--------------------------------------------------------------------------*/
3375 static FIELD *
3376 Upper_Neighbor_Field(FIELD *field)
3377 {
3378   FIELD *field_on_page = field;
3379   int frow = field->frow;
3380   int fcol = field->fcol;
3381
3382   /* Walk back to the 'previous' line. The second term in the while clause
3383      just guarantees that we stop if we cycled through the line because
3384      there might be no 'previous' line if the page has just one line.
3385    */
3386   do
3387     {
3388       field_on_page = Sorted_Previous_Field(field_on_page);
3389     }
3390   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3391
3392   if (field_on_page->frow != frow)
3393     {
3394       /* We really found a 'previous' line. We are positioned at the
3395          rightmost field on this line */
3396       frow = field_on_page->frow;
3397
3398       /* We walk to the left as long as we are really right of the
3399          field. */
3400       while (field_on_page->frow == frow && field_on_page->fcol > fcol)
3401         field_on_page = Sorted_Previous_Field(field_on_page);
3402
3403       /* If we wrapped, just go to the right which is the first field on
3404          the row */
3405       if (field_on_page->frow != frow)
3406         field_on_page = Sorted_Next_Field(field_on_page);
3407     }
3408
3409   return (field_on_page);
3410 }
3411
3412 /*---------------------------------------------------------------------------
3413 |   Facility      :  libnform
3414 |   Function      :  static FIELD *Down_Neighbor_Field(FIELD * field)
3415 |
3416 |   Description   :  Because of the row-major nature of sorting the fields,
3417 |                    its more difficult to define whats the down neighbor
3418 |                    field really means. We define that it must be on a
3419 |                    'next' line (cyclic order!) and is the leftmost
3420 |                    field laying on the right side of the given field. If
3421 |                    this set is empty, we take the last field on the line.
3422 |
3423 |   Return Values :  Pointer to the upper neighbor field.
3424 +--------------------------------------------------------------------------*/
3425 static FIELD *
3426 Down_Neighbor_Field(FIELD *field)
3427 {
3428   FIELD *field_on_page = field;
3429   int frow = field->frow;
3430   int fcol = field->fcol;
3431
3432   /* Walk forward to the 'next' line. The second term in the while clause
3433      just guarantees that we stop if we cycled through the line because
3434      there might be no 'next' line if the page has just one line.
3435    */
3436   do
3437     {
3438       field_on_page = Sorted_Next_Field(field_on_page);
3439     }
3440   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3441
3442   if (field_on_page->frow != frow)
3443     {
3444       /* We really found a 'next' line. We are positioned at the rightmost
3445          field on this line */
3446       frow = field_on_page->frow;
3447
3448       /* We walk to the right as long as we are really left of the
3449          field. */
3450       while (field_on_page->frow == frow && field_on_page->fcol < fcol)
3451         field_on_page = Sorted_Next_Field(field_on_page);
3452
3453       /* If we wrapped, just go to the left which is the last field on
3454          the row */
3455       if (field_on_page->frow != frow)
3456         field_on_page = Sorted_Previous_Field(field_on_page);
3457     }
3458
3459   return (field_on_page);
3460 }
3461
3462 /*----------------------------------------------------------------------------
3463   Inter-Field Navigation routines
3464   --------------------------------------------------------------------------*/
3465
3466 /*---------------------------------------------------------------------------
3467 |   Facility      :  libnform
3468 |   Function      :  static int Inter_Field_Navigation(
3469 |                                           int (* const fct) (FORM *),
3470 |                                           FORM * form)
3471 |
3472 |   Description   :  Generic behavior for changing the current field, the
3473 |                    field is left and a new field is entered. So the field
3474 |                    must be validated and the field init/term hooks must
3475 |                    be called.
3476 |
3477 |   Return Values :  E_OK                - success
3478 |                    E_INVALID_FIELD     - field is invalid
3479 |                    some other          - error from subordinate call
3480 +--------------------------------------------------------------------------*/
3481 static int
3482 Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form)
3483 {
3484   int res;
3485
3486   if (!_nc_Internal_Validation(form))
3487     res = E_INVALID_FIELD;
3488   else
3489     {
3490       Call_Hook(form, fieldterm);
3491       res = fct(form);
3492       Call_Hook(form, fieldinit);
3493     }
3494   return res;
3495 }
3496
3497 /*---------------------------------------------------------------------------
3498 |   Facility      :  libnform
3499 |   Function      :  static int FN_Next_Field(FORM * form)
3500 |
3501 |   Description   :  Move to the next field on the current page of the form
3502 |
3503 |   Return Values :  E_OK                 - success
3504 |                    != E_OK              - error from subordinate call
3505 +--------------------------------------------------------------------------*/
3506 static int
3507 FN_Next_Field(FORM *form)
3508 {
3509   T((T_CALLED("FN_Next_Field(%p)"), form));
3510   returnCode(_nc_Set_Current_Field(form,
3511                                    Next_Field_On_Page(form->current)));
3512 }
3513
3514 /*---------------------------------------------------------------------------
3515 |   Facility      :  libnform
3516 |   Function      :  static int FN_Previous_Field(FORM * form)
3517 |
3518 |   Description   :  Move to the previous field on the current page of the
3519 |                    form
3520 |
3521 |   Return Values :  E_OK                 - success
3522 |                    != E_OK              - error from subordinate call
3523 +--------------------------------------------------------------------------*/
3524 static int
3525 FN_Previous_Field(FORM *form)
3526 {
3527   T((T_CALLED("FN_Previous_Field(%p)"), form));
3528   returnCode(_nc_Set_Current_Field(form,
3529                                    Previous_Field_On_Page(form->current)));
3530 }
3531
3532 /*---------------------------------------------------------------------------
3533 |   Facility      :  libnform
3534 |   Function      :  static int FN_First_Field(FORM * form)
3535 |
3536 |   Description   :  Move to the first field on the current page of the form
3537 |
3538 |   Return Values :  E_OK                 - success
3539 |                    != E_OK              - error from subordinate call
3540 +--------------------------------------------------------------------------*/
3541 static int
3542 FN_First_Field(FORM *form)
3543 {
3544   T((T_CALLED("FN_First_Field(%p)"), form));
3545   returnCode(_nc_Set_Current_Field(form,
3546                                    Next_Field_On_Page(form->field[form->page[form->curpage].pmax])));
3547 }
3548
3549 /*---------------------------------------------------------------------------
3550 |   Facility      :  libnform
3551 |   Function      :  static int FN_Last_Field(FORM * form)
3552 |
3553 |   Description   :  Move to the last field on the current page of the form
3554 |
3555 |   Return Values :  E_OK                 - success
3556 |                    != E_OK              - error from subordinate call
3557 +--------------------------------------------------------------------------*/
3558 static int
3559 FN_Last_Field(FORM *form)
3560 {
3561   T((T_CALLED("FN_Last_Field(%p)"), form));
3562   returnCode(
3563               _nc_Set_Current_Field(form,
3564                                     Previous_Field_On_Page(form->field[form->page[form->curpage].pmin])));
3565 }
3566
3567 /*---------------------------------------------------------------------------
3568 |   Facility      :  libnform
3569 |   Function      :  static int FN_Sorted_Next_Field(FORM * form)
3570 |
3571 |   Description   :  Move to the sorted next field on the current page
3572 |                    of the form.
3573 |
3574 |   Return Values :  E_OK            - success
3575 |                    != E_OK         - error from subordinate call
3576 +--------------------------------------------------------------------------*/
3577 static int
3578 FN_Sorted_Next_Field(FORM *form)
3579 {
3580   T((T_CALLED("FN_Sorted_Next_Field(%p)"), form));
3581   returnCode(_nc_Set_Current_Field(form,
3582                                    Sorted_Next_Field(form->current)));
3583 }
3584
3585 /*---------------------------------------------------------------------------
3586 |   Facility      :  libnform
3587 |   Function      :  static int FN_Sorted_Previous_Field(FORM * form)
3588 |
3589 |   Description   :  Move to the sorted previous field on the current page
3590 |                    of the form.
3591 |
3592 |   Return Values :  E_OK            - success
3593 |                    != E_OK         - error from subordinate call
3594 +--------------------------------------------------------------------------*/
3595 static int
3596 FN_Sorted_Previous_Field(FORM *form)
3597 {
3598   T((T_CALLED("FN_Sorted_Previous_Field(%p)"), form));
3599   returnCode(_nc_Set_Current_Field(form,
3600                                    Sorted_Previous_Field(form->current)));
3601 }
3602
3603 /*---------------------------------------------------------------------------
3604 |   Facility      :  libnform
3605 |   Function      :  static int FN_Sorted_First_Field(FORM * form)
3606 |
3607 |   Description   :  Move to the sorted first field on the current page
3608 |                    of the form.
3609 |
3610 |   Return Values :  E_OK            - success
3611 |                    != E_OK         - error from subordinate call
3612 +--------------------------------------------------------------------------*/
3613 static int
3614 FN_Sorted_First_Field(FORM *form)
3615 {
3616   T((T_CALLED("FN_Sorted_First_Field(%p)"), form));
3617   returnCode(_nc_Set_Current_Field(form,
3618                                    Sorted_Next_Field(form->field[form->page[form->curpage].smax])));
3619 }
3620
3621 /*---------------------------------------------------------------------------
3622 |   Facility      :  libnform
3623 |   Function      :  static int FN_Sorted_Last_Field(FORM * form)
3624 |
3625 |   Description   :  Move to the sorted last field on the current page
3626 |                    of the form.
3627 |
3628 |   Return Values :  E_OK            - success
3629 |                    != E_OK         - error from subordinate call
3630 +--------------------------------------------------------------------------*/
3631 static int
3632 FN_Sorted_Last_Field(FORM *form)
3633 {
3634   T((T_CALLED("FN_Sorted_Last_Field(%p)"), form));
3635   returnCode(_nc_Set_Current_Field(form,
3636                                    Sorted_Previous_Field(form->field[form->page[form->curpage].smin])));
3637 }
3638
3639 /*---------------------------------------------------------------------------
3640 |   Facility      :  libnform
3641 |   Function      :  static int FN_Left_Field(FORM * form)
3642 |
3643 |   Description   :  Get the field on the left of the current field on the
3644 |                    same line and the same page. Cycles through the line.
3645 |
3646 |   Return Values :  E_OK            - success
3647 |                    != E_OK         - error from subordinate call
3648 +--------------------------------------------------------------------------*/
3649 static int
3650 FN_Left_Field(FORM *form)
3651 {
3652   T((T_CALLED("FN_Left_Field(%p)"), form));
3653   returnCode(_nc_Set_Current_Field(form,
3654                                    Left_Neighbor_Field(form->current)));
3655 }
3656
3657 /*---------------------------------------------------------------------------
3658 |   Facility      :  libnform
3659 |   Function      :  static int FN_Right_Field(FORM * form)
3660 |
3661 |   Description   :  Get the field on the right of the current field on the
3662 |                    same line and the same page. Cycles through the line.
3663 |
3664 |   Return Values :  E_OK            - success
3665 |                    != E_OK         - error from subordinate call
3666 +--------------------------------------------------------------------------*/
3667 static int
3668 FN_Right_Field(FORM *form)
3669 {
3670   T((T_CALLED("FN_Right_Field(%p)"), form));
3671   returnCode(_nc_Set_Current_Field(form,
3672                                    Right_Neighbor_Field(form->current)));
3673 }
3674
3675 /*---------------------------------------------------------------------------
3676 |   Facility      :  libnform
3677 |   Function      :  static int FN_Up_Field(FORM * form)
3678 |
3679 |   Description   :  Get the upper neighbor of the current field. This
3680 |                    cycles through the page. See the comments of the
3681 |                    Upper_Neighbor_Field function to understand how
3682 |                    'upper' is defined.
3683 |
3684 |   Return Values :  E_OK            - success
3685 |                    != E_OK         - error from subordinate call
3686 +--------------------------------------------------------------------------*/
3687 static int
3688 FN_Up_Field(FORM *form)
3689 {
3690   T((T_CALLED("FN_Up_Field(%p)"), form));
3691   returnCode(_nc_Set_Current_Field(form,
3692                                    Upper_Neighbor_Field(form->current)));
3693 }
3694
3695 /*---------------------------------------------------------------------------
3696 |   Facility      :  libnform
3697 |   Function      :  static int FN_Down_Field(FORM * form)
3698 |
3699 |   Description   :  Get the down neighbor of the current field. This
3700 |                    cycles through the page. See the comments of the
3701 |                    Down_Neighbor_Field function to understand how
3702 |                    'down' is defined.
3703 |
3704 |   Return Values :  E_OK            - success
3705 |                    != E_OK         - error from subordinate call
3706 +--------------------------------------------------------------------------*/
3707 static int
3708 FN_Down_Field(FORM *form)
3709 {
3710   T((T_CALLED("FN_Down_Field(%p)"), form));
3711   returnCode(_nc_Set_Current_Field(form,
3712                                    Down_Neighbor_Field(form->current)));
3713 }
3714 /*----------------------------------------------------------------------------
3715   END of Field Navigation routines
3716   --------------------------------------------------------------------------*/
3717
3718 /*----------------------------------------------------------------------------
3719   Helper routines for Page Navigation
3720   --------------------------------------------------------------------------*/
3721
3722 /*---------------------------------------------------------------------------
3723 |   Facility      :  libnform
3724 |   Function      :  int _nc_Set_Form_Page(FORM * form,
3725 |                                          int page,
3726 |                                          FIELD * field)
3727 |
3728 |   Description   :  Make the given page number the current page and make
3729 |                    the given field the current field on the page. If
3730 |                    for the field NULL is given, make the first field on
3731 |                    the page the current field. The routine acts only
3732 |                    if the requested page is not the current page.
3733 |
3734 |   Return Values :  E_OK                - success
3735 |                    != E_OK             - error from subordinate call
3736 |                    E_BAD_ARGUMENT      - invalid field pointer
3737 |                    E_SYSTEM_ERROR      - some severe basic error
3738 +--------------------------------------------------------------------------*/
3739 NCURSES_EXPORT(int)
3740 _nc_Set_Form_Page(FORM *form, int page, FIELD *field)
3741 {
3742   int res = E_OK;
3743
3744   if ((form->curpage != page))
3745     {
3746       FIELD *last_field, *field_on_page;
3747
3748       werase(Get_Form_Window(form));
3749       form->curpage = page;
3750       last_field = field_on_page = form->field[form->page[page].smin];
3751       do
3752         {
3753           if (field_on_page->opts & O_VISIBLE)
3754             if ((res = Display_Field(field_on_page)) != E_OK)
3755               return (res);
3756           field_on_page = field_on_page->snext;
3757         }
3758       while (field_on_page != last_field);
3759
3760       if (field)
3761         res = _nc_Set_Current_Field(form, field);
3762       else
3763         /* N.B.: we don't encapsulate this by Inter_Field_Navigation(),
3764            because this is already executed in a page navigation
3765            context that contains field navigation
3766          */
3767         res = FN_First_Field(form);
3768     }
3769   return (res);
3770 }
3771
3772 /*---------------------------------------------------------------------------
3773 |   Facility      :  libnform
3774 |   Function      :  static int Next_Page_Number(const FORM * form)
3775 |
3776 |   Description   :  Calculate the page number following the current page
3777 |                    number. This cycles if the highest page number is
3778 |                    reached.
3779 |
3780 |   Return Values :  The next page number
3781 +--------------------------------------------------------------------------*/
3782 NCURSES_INLINE static int
3783 Next_Page_Number(const FORM *form)
3784 {
3785   return (form->curpage + 1) % form->maxpage;
3786 }
3787
3788 /*---------------------------------------------------------------------------
3789 |   Facility      :  libnform
3790 |   Function      :  static int Previous_Page_Number(const FORM * form)
3791 |
3792 |   Description   :  Calculate the page number before the current page
3793 |                    number. This cycles if the first page number is
3794 |                    reached.
3795 |
3796 |   Return Values :  The previous page number
3797 +--------------------------------------------------------------------------*/
3798 NCURSES_INLINE static int
3799 Previous_Page_Number(const FORM *form)
3800 {
3801   return (form->curpage != 0 ? form->curpage - 1 : form->maxpage - 1);
3802 }
3803
3804 /*----------------------------------------------------------------------------
3805   Page Navigation routines
3806   --------------------------------------------------------------------------*/
3807
3808 /*---------------------------------------------------------------------------
3809 |   Facility      :  libnform
3810 |   Function      :  static int Page_Navigation(
3811 |                                               int (* const fct) (FORM *),
3812 |                                               FORM * form)
3813 |
3814 |   Description   :  Generic behavior for changing a page. This means
3815 |                    that the field is left and a new field is entered.
3816 |                    So the field must be validated and the field init/term
3817 |                    hooks must be called. Because also the page is changed,
3818 |                    the forms init/term hooks must be called also.
3819 |
3820 |   Return Values :  E_OK                - success
3821 |                    E_INVALID_FIELD     - field is invalid
3822 |                    some other          - error from subordinate call
3823 +--------------------------------------------------------------------------*/
3824 static int
3825 Page_Navigation(int (*const fct) (FORM *), FORM *form)
3826 {
3827   int res;
3828
3829   if (!_nc_Internal_Validation(form))
3830     res = E_INVALID_FIELD;
3831   else
3832     {
3833       Call_Hook(form, fieldterm);
3834       Call_Hook(form, formterm);
3835       res = fct(form);
3836       Call_Hook(form, forminit);
3837       Call_Hook(form, fieldinit);
3838     }
3839   return res;
3840 }
3841
3842 /*---------------------------------------------------------------------------
3843 |   Facility      :  libnform
3844 |   Function      :  static int PN_Next_Page(FORM * form)
3845 |
3846 |   Description   :  Move to the next page of the form
3847 |
3848 |   Return Values :  E_OK                - success
3849 |                    != E_OK             - error from subordinate call
3850 +--------------------------------------------------------------------------*/
3851 static int
3852 PN_Next_Page(FORM *form)
3853 {
3854   T((T_CALLED("PN_Next_Page(%p)"), form));
3855   returnCode(_nc_Set_Form_Page(form, Next_Page_Number(form), (FIELD *)0));
3856 }
3857
3858 /*---------------------------------------------------------------------------
3859 |   Facility      :  libnform
3860 |   Function      :  static int PN_Previous_Page(FORM * form)
3861 |
3862 |   Description   :  Move to the previous page of the form
3863 |
3864 |   Return Values :  E_OK              - success
3865 |                    != E_OK           - error from subordinate call
3866 +--------------------------------------------------------------------------*/
3867 static int
3868 PN_Previous_Page(FORM *form)
3869 {
3870   T((T_CALLED("PN_Previous_Page(%p)"), form));
3871   returnCode(_nc_Set_Form_Page(form, Previous_Page_Number(form), (FIELD *)0));
3872 }
3873
3874 /*---------------------------------------------------------------------------
3875 |   Facility      :  libnform
3876 |   Function      :  static int PN_First_Page(FORM * form)
3877 |
3878 |   Description   :  Move to the first page of the form
3879 |
3880 |   Return Values :  E_OK              - success
3881 |                    != E_OK           - error from subordinate call
3882 +--------------------------------------------------------------------------*/
3883 static int
3884 PN_First_Page(FORM *form)
3885 {
3886   T((T_CALLED("PN_First_Page(%p)"), form));
3887   returnCode(_nc_Set_Form_Page(form, 0, (FIELD *)0));
3888 }
3889
3890 /*---------------------------------------------------------------------------
3891 |   Facility      :  libnform
3892 |   Function      :  static int PN_Last_Page(FORM * form)
3893 |
3894 |   Description   :  Move to the last page of the form
3895 |
3896 |   Return Values :  E_OK              - success
3897 |                    != E_OK           - error from subordinate call
3898 +--------------------------------------------------------------------------*/
3899 static int
3900 PN_Last_Page(FORM *form)
3901 {
3902   T((T_CALLED("PN_Last_Page(%p)"), form));
3903   returnCode(_nc_Set_Form_Page(form, form->maxpage - 1, (FIELD *)0));
3904 }
3905
3906 /*----------------------------------------------------------------------------
3907   END of Field Navigation routines
3908   --------------------------------------------------------------------------*/
3909
3910 /*----------------------------------------------------------------------------
3911   Helper routines for the core form driver.
3912   --------------------------------------------------------------------------*/
3913
3914 /*---------------------------------------------------------------------------
3915 |   Facility      :  libnform
3916 |   Function      :  static int Data_Entry(FORM * form,int c)
3917 |
3918 |   Description   :  Enter character c into at the current position of the
3919 |                    current field of the form.
3920 |
3921 |   Return Values :  E_OK              - success
3922 |                    E_REQUEST_DENIED  - driver could not process the request
3923 |                    E_SYSTEM_ERROR    -
3924 +--------------------------------------------------------------------------*/
3925 static int
3926 Data_Entry(FORM *form, int c)
3927 {
3928   FIELD *field = form->current;
3929   int result = E_REQUEST_DENIED;
3930
3931   T((T_CALLED("Data_Entry(%p,%s)"), form, _tracechtype((chtype)c)));
3932   if ((field->opts & O_EDIT)
3933 #if FIX_FORM_INACTIVE_BUG
3934       && (field->opts & O_ACTIVE)
3935 #endif
3936     )
3937     {
3938       if ((field->opts & O_BLANK) &&
3939           First_Position_In_Current_Field(form) &&
3940           !(form->status & _FCHECK_REQUIRED) &&
3941           !(form->status & _WINDOW_MODIFIED))
3942         werase(form->w);
3943
3944       if (form->status & _OVLMODE)
3945         {
3946           waddch(form->w, (chtype)c);
3947         }
3948       else
3949         /* no _OVLMODE */
3950         {
3951           bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
3952
3953           if (!(There_Is_Room ||
3954                 ((Single_Line_Field(field) && Growable(field)))))
3955             RETURN(E_REQUEST_DENIED);
3956
3957           if (!There_Is_Room && !Field_Grown(field, 1))
3958             RETURN(E_SYSTEM_ERROR);
3959
3960           winsch(form->w, (chtype)c);
3961         }
3962
3963       if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
3964         {
3965           bool End_Of_Field = (((field->drows - 1) == form->currow) &&
3966                                ((field->dcols - 1) == form->curcol));
3967
3968           form->status |= _WINDOW_MODIFIED;
3969           if (End_Of_Field && !Growable(field) && (field->opts & O_AUTOSKIP))
3970             result = Inter_Field_Navigation(FN_Next_Field, form);
3971           else
3972             {
3973               if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
3974                 result = E_SYSTEM_ERROR;
3975               else
3976                 {
3977 #if USE_WIDEC_SUPPORT
3978                   /*
3979                    * We have just added a byte to the form field.  It may have
3980                    * been part of a multibyte character.  If it was, the
3981                    * addch_used field is nonzero and we should not try to move
3982                    * to a new column.
3983                    */
3984                   if (WINDOW_EXT(form->w, addch_used) == 0)
3985                     IFN_Next_Character(form);
3986 #else
3987                   IFN_Next_Character(form);
3988 #endif
3989                   result = E_OK;
3990                 }
3991             }
3992         }
3993     }
3994   RETURN(result);
3995 }
3996
3997 /* Structure to describe the binding of a request code to a function.
3998    The member keycode codes the request value as well as the generic
3999    routine to use for the request. The code for the generic routine
4000    is coded in the upper 16 Bits while the request code is coded in
4001    the lower 16 bits.
4002
4003    In terms of C++ you might think of a request as a class with a
4004    virtual method "perform". The different types of request are
4005    derived from this base class and overload (or not) the base class
4006    implementation of perform.
4007 */
4008 typedef struct
4009 {
4010   int keycode;                  /* must be at least 32 bit: hi:mode, lo: key */
4011   int (*cmd) (FORM *);          /* low level driver routine for this key     */
4012 }
4013 Binding_Info;
4014
4015 /* You may see this is the class-id of the request type class */
4016 #define ID_PN    (0x00000000)   /* Page navigation           */
4017 #define ID_FN    (0x00010000)   /* Inter-Field navigation    */
4018 #define ID_IFN   (0x00020000)   /* Intra-Field navigation    */
4019 #define ID_VSC   (0x00030000)   /* Vertical Scrolling        */
4020 #define ID_HSC   (0x00040000)   /* Horizontal Scrolling      */
4021 #define ID_FE    (0x00050000)   /* Field Editing             */
4022 #define ID_EM    (0x00060000)   /* Edit Mode                 */
4023 #define ID_FV    (0x00070000)   /* Field Validation          */
4024 #define ID_CH    (0x00080000)   /* Choice                    */
4025 #define ID_Mask  (0xffff0000)
4026 #define Key_Mask (0x0000ffff)
4027 #define ID_Shft  (16)
4028
4029 /* This array holds all the Binding Infos */
4030 /* *INDENT-OFF* */
4031 static const Binding_Info bindings[MAX_FORM_COMMAND - MIN_FORM_COMMAND + 1] =
4032 {
4033   { REQ_NEXT_PAGE    |ID_PN  ,PN_Next_Page},
4034   { REQ_PREV_PAGE    |ID_PN  ,PN_Previous_Page},
4035   { REQ_FIRST_PAGE   |ID_PN  ,PN_First_Page},
4036   { REQ_LAST_PAGE    |ID_PN  ,PN_Last_Page},
4037
4038   { REQ_NEXT_FIELD   |ID_FN  ,FN_Next_Field},
4039   { REQ_PREV_FIELD   |ID_FN  ,FN_Previous_Field},
4040   { REQ_FIRST_FIELD  |ID_FN  ,FN_First_Field},
4041   { REQ_LAST_FIELD   |ID_FN  ,FN_Last_Field},
4042   { REQ_SNEXT_FIELD  |ID_FN  ,FN_Sorted_Next_Field},
4043   { REQ_SPREV_FIELD  |ID_FN  ,FN_Sorted_Previous_Field},
4044   { REQ_SFIRST_FIELD |ID_FN  ,FN_Sorted_First_Field},
4045   { REQ_SLAST_FIELD  |ID_FN  ,FN_Sorted_Last_Field},
4046   { REQ_LEFT_FIELD   |ID_FN  ,FN_Left_Field},
4047   { REQ_RIGHT_FIELD  |ID_FN  ,FN_Right_Field},
4048   { REQ_UP_FIELD     |ID_FN  ,FN_Up_Field},
4049   { REQ_DOWN_FIELD   |ID_FN  ,FN_Down_Field},
4050
4051   { REQ_NEXT_CHAR    |ID_IFN ,IFN_Next_Character},
4052   { REQ_PREV_CHAR    |ID_IFN ,IFN_Previous_Character},
4053   { REQ_NEXT_LINE    |ID_IFN ,IFN_Next_Line},
4054   { REQ_PREV_LINE    |ID_IFN ,IFN_Previous_Line},
4055   { REQ_NEXT_WORD    |ID_IFN ,IFN_Next_Word},
4056   { REQ_PREV_WORD    |ID_IFN ,IFN_Previous_Word},
4057   { REQ_BEG_FIELD    |ID_IFN ,IFN_Beginning_Of_Field},
4058   { REQ_END_FIELD    |ID_IFN ,IFN_End_Of_Field},
4059   { REQ_BEG_LINE     |ID_IFN ,IFN_Beginning_Of_Line},
4060   { REQ_END_LINE     |ID_IFN ,IFN_End_Of_Line},
4061   { REQ_LEFT_CHAR    |ID_IFN ,IFN_Left_Character},
4062   { REQ_RIGHT_CHAR   |ID_IFN ,IFN_Right_Character},
4063   { REQ_UP_CHAR      |ID_IFN ,IFN_Up_Character},
4064   { REQ_DOWN_CHAR    |ID_IFN ,IFN_Down_Character},
4065
4066   { REQ_NEW_LINE     |ID_FE  ,FE_New_Line},
4067   { REQ_INS_CHAR     |ID_FE  ,FE_Insert_Character},
4068   { REQ_INS_LINE     |ID_FE  ,FE_Insert_Line},
4069   { REQ_DEL_CHAR     |ID_FE  ,FE_Delete_Character},
4070   { REQ_DEL_PREV     |ID_FE  ,FE_Delete_Previous},
4071   { REQ_DEL_LINE     |ID_FE  ,FE_Delete_Line},
4072   { REQ_DEL_WORD     |ID_FE  ,FE_Delete_Word},
4073   { REQ_CLR_EOL      |ID_FE  ,FE_Clear_To_End_Of_Line},
4074   { REQ_CLR_EOF      |ID_FE  ,FE_Clear_To_End_Of_Field},
4075   { REQ_CLR_FIELD    |ID_FE  ,FE_Clear_Field},
4076
4077   { REQ_OVL_MODE     |ID_EM  ,EM_Overlay_Mode},
4078   { REQ_INS_MODE     |ID_EM  ,EM_Insert_Mode},
4079
4080   { REQ_SCR_FLINE    |ID_VSC ,VSC_Scroll_Line_Forward},
4081   { REQ_SCR_BLINE    |ID_VSC ,VSC_Scroll_Line_Backward},
4082   { REQ_SCR_FPAGE    |ID_VSC ,VSC_Scroll_Page_Forward},
4083   { REQ_SCR_BPAGE    |ID_VSC ,VSC_Scroll_Page_Backward},
4084   { REQ_SCR_FHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Forward},
4085   { REQ_SCR_BHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Backward},
4086
4087   { REQ_SCR_FCHAR    |ID_HSC ,HSC_Scroll_Char_Forward},
4088   { REQ_SCR_BCHAR    |ID_HSC ,HSC_Scroll_Char_Backward},
4089   { REQ_SCR_HFLINE   |ID_HSC ,HSC_Horizontal_Line_Forward},
4090   { REQ_SCR_HBLINE   |ID_HSC ,HSC_Horizontal_Line_Backward},
4091   { REQ_SCR_HFHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Forward},
4092   { REQ_SCR_HBHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Backward},
4093
4094   { REQ_VALIDATION   |ID_FV  ,FV_Validation},
4095
4096   { REQ_NEXT_CHOICE  |ID_CH  ,CR_Next_Choice},
4097   { REQ_PREV_CHOICE  |ID_CH  ,CR_Previous_Choice}
4098 };
4099 /* *INDENT-ON* */
4100
4101 /*---------------------------------------------------------------------------
4102 |   Facility      :  libnform
4103 |   Function      :  int form_driver(FORM * form,int  c)
4104 |
4105 |   Description   :  This is the workhorse of the forms system. It checks
4106 |                    to determine whether the character c is a request or
4107 |                    data. If it is a request, the form driver executes
4108 |                    the request and returns the result. If it is data
4109 |                    (printable character), it enters the data into the
4110 |                    current position in the current field. If it is not
4111 |                    recognized, the form driver assumes it is an application
4112 |                    defined command and returns E_UNKNOWN_COMMAND.
4113 |                    Application defined command should be defined relative
4114 |                    to MAX_FORM_COMMAND, the maximum value of a request.
4115 |
4116 |   Return Values :  E_OK              - success
4117 |                    E_SYSTEM_ERROR    - system error
4118 |                    E_BAD_ARGUMENT    - an argument is incorrect
4119 |                    E_NOT_POSTED      - form is not posted
4120 |                    E_INVALID_FIELD   - field contents are invalid
4121 |                    E_BAD_STATE       - called from inside a hook routine
4122 |                    E_REQUEST_DENIED  - request failed
4123 |                    E_NOT_CONNECTED   - no fields are connected to the form
4124 |                    E_UNKNOWN_COMMAND - command not known
4125 +--------------------------------------------------------------------------*/
4126 NCURSES_EXPORT(int)
4127 form_driver(FORM *form, int c)
4128 {
4129   const Binding_Info *BI = (Binding_Info *) 0;
4130   int res = E_UNKNOWN_COMMAND;
4131
4132   T((T_CALLED("form_driver(%p,%d)"), form, c));
4133
4134   if (!form)
4135     RETURN(E_BAD_ARGUMENT);
4136
4137   if (!(form->field))
4138     RETURN(E_NOT_CONNECTED);
4139
4140   assert(form->page);
4141
4142   if (c == FIRST_ACTIVE_MAGIC)
4143     {
4144       form->current = _nc_First_Active_Field(form);
4145       RETURN(E_OK);
4146     }
4147
4148   assert(form->current &&
4149          form->current->buf &&
4150          (form->current->form == form)
4151     );
4152
4153   if (form->status & _IN_DRIVER)
4154     RETURN(E_BAD_STATE);
4155
4156   if (!(form->status & _POSTED))
4157     RETURN(E_NOT_POSTED);
4158
4159   if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4160       ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4161     BI = &(bindings[c - MIN_FORM_COMMAND]);
4162
4163   if (BI)
4164     {
4165       typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4166       static const Generic_Method Generic_Methods[] =
4167       {
4168         Page_Navigation,        /* overloaded to call field&form hooks */
4169         Inter_Field_Navigation, /* overloaded to call field hooks      */
4170         NULL,                   /* Intra-Field is generic              */
4171         Vertical_Scrolling,     /* Overloaded to check multi-line      */
4172         Horizontal_Scrolling,   /* Overloaded to check single-line     */
4173         Field_Editing,          /* Overloaded to mark modification     */
4174         NULL,                   /* Edit Mode is generic                */
4175         NULL,                   /* Field Validation is generic         */
4176         NULL                    /* Choice Request is generic           */
4177       };
4178       size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4179       size_t method = ((BI->keycode & ID_Mask) >> ID_Shft) & 0xffff;
4180
4181       if ((method >= nMethods) || !(BI->cmd))
4182         res = E_SYSTEM_ERROR;
4183       else
4184         {
4185           Generic_Method fct = Generic_Methods[method];
4186
4187           if (fct)
4188             res = fct(BI->cmd, form);
4189           else
4190             res = (BI->cmd) (form);
4191         }
4192     }
4193 #ifdef NCURSES_MOUSE_VERSION
4194   else if (KEY_MOUSE == c)
4195     {
4196       MEVENT event;
4197       WINDOW *win = form->win ? form->win : stdscr;
4198       WINDOW *sub = form->sub ? form->sub : win;
4199
4200       getmouse(&event);
4201       if ((event.bstate & (BUTTON1_CLICKED |
4202                            BUTTON1_DOUBLE_CLICKED |
4203                            BUTTON1_TRIPLE_CLICKED))
4204           && wenclose(win, event.y, event.x))
4205         {                       /* we react only if the click was in the userwin, that means
4206                                  * inside the form display area or at the decoration window.
4207                                  */
4208           int ry = event.y, rx = event.x;       /* screen coordinates */
4209
4210           res = E_REQUEST_DENIED;
4211           if (mouse_trafo(&ry, &rx, FALSE))
4212             {                   /* rx, ry are now "curses" coordinates */
4213               if (ry < sub->_begy)
4214                 {               /* we clicked above the display region; this is
4215                                  * interpreted as "scroll up" request
4216                                  */
4217                   if (event.bstate & BUTTON1_CLICKED)
4218                     res = form_driver(form, REQ_PREV_FIELD);
4219                   else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4220                     res = form_driver(form, REQ_PREV_PAGE);
4221                   else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4222                     res = form_driver(form, REQ_FIRST_FIELD);
4223                 }
4224               else if (ry > sub->_begy + sub->_maxy)
4225                 {               /* we clicked below the display region; this is
4226                                  * interpreted as "scroll down" request
4227                                  */
4228                   if (event.bstate & BUTTON1_CLICKED)
4229                     res = form_driver(form, REQ_NEXT_FIELD);
4230                   else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4231                     res = form_driver(form, REQ_NEXT_PAGE);
4232                   else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4233                     res = form_driver(form, REQ_LAST_FIELD);
4234                 }
4235               else if (wenclose(sub, event.y, event.x))
4236                 {               /* Inside the area we try to find the hit item */
4237                   int i;
4238
4239                   ry = event.y;
4240                   rx = event.x;
4241                   if (wmouse_trafo(sub, &ry, &rx, FALSE))
4242                     {
4243                       int min_field = form->page[form->curpage].pmin;
4244                       int max_field = form->page[form->curpage].pmax;
4245
4246                       for (i = min_field; i <= max_field; ++i)
4247                         {
4248                           FIELD *field = form->field[i];
4249
4250                           if (Field_Is_Selectable(field)
4251                               && Field_encloses(field, ry, rx) == E_OK)
4252                             {
4253                               res = _nc_Set_Current_Field(form, field);
4254                               if (res == E_OK)
4255                                 res = _nc_Position_Form_Cursor(form);
4256                               if (res == E_OK
4257                                   && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4258                                 res = E_UNKNOWN_COMMAND;
4259                               break;
4260                             }
4261                         }
4262                     }
4263                 }
4264             }
4265         }
4266       else
4267         res = E_REQUEST_DENIED;
4268     }
4269 #endif /* NCURSES_MOUSE_VERSION */
4270   else if (!(c & (~(int)MAX_REGULAR_CHARACTER)))
4271     {
4272       /*
4273        * If we're using 8-bit characters, iscntrl+isprint cover the whole set.
4274        * But with multibyte characters, there is a third possibility, i.e.,
4275        * parts of characters that build up into printable characters which are
4276        * not considered printable.
4277        *
4278        * FIXME: the wide-character branch should also use Check_Char().
4279        */
4280 #if USE_WIDEC_SUPPORT
4281       if (!iscntrl(UChar(c)))
4282 #else
4283       if (isprint(UChar(c)) &&
4284           Check_Char(form->current->type, c,
4285                      (TypeArgument *)(form->current->arg)))
4286 #endif
4287         res = Data_Entry(form, c);
4288     }
4289   _nc_Refresh_Current_Field(form);
4290   RETURN(res);
4291 }
4292
4293 /*----------------------------------------------------------------------------
4294   Field-Buffer manipulation routines.
4295   The effects of setting a buffer are tightly coupled to the core of the form
4296   driver logic. This is especially true in the case of growable fields.
4297   So I don't separate this into a separate module.
4298   --------------------------------------------------------------------------*/
4299
4300 /*---------------------------------------------------------------------------
4301 |   Facility      :  libnform
4302 |   Function      :  int set_field_buffer(FIELD *field,
4303 |                                         int buffer, char *value)
4304 |
4305 |   Description   :  Set the given buffer of the field to the given value.
4306 |                    Buffer 0 stores the displayed content of the field.
4307 |                    For dynamic fields this may grow the fieldbuffers if
4308 |                    the length of the value exceeds the current buffer
4309 |                    length. For buffer 0 only printable values are allowed.
4310 |                    For static fields, the value needs not to be zero ter-
4311 |                    minated. It is copied up to the length of the buffer.
4312 |
4313 |   Return Values :  E_OK            - success
4314 |                    E_BAD_ARGUMENT  - invalid argument
4315 |                    E_SYSTEM_ERROR  - system error
4316 +--------------------------------------------------------------------------*/
4317 NCURSES_EXPORT(int)
4318 set_field_buffer(FIELD *field, int buffer, const char *value)
4319 {
4320   FIELD_CELL *p;
4321   int res =&nbs