form/frm_driver.c

   1 /****************************************************************************
   2  * Copyright (c) 1998-2008,2009 Free Software Foundation, Inc.              *
   3  *                                                                          *
   4  * Permission is hereby granted, free of charge, to any person obtaining a  *
   5  * copy of this software and associated documentation files (the            *
   6  * "Software"), to deal in the Software without restriction, including      *
   7  * without limitation the rights to use, copy, modify, merge, publish,      *
   8  * distribute, distribute with modifications, sublicense, and/or sell       *
   9  * copies of the Software, and to permit persons to whom the Software is    *
  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
  12  * The above copyright notice and this permission notice shall be included  *
  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    *
  20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  22  *                                                                          *
  23  * Except as contained in this notice, the name(s) of the above copyright   *
  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 1.95 2009/12/05 21:45:58 Rafael.Garrido.Fernandez 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    (void) 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      :  void _nc_get_fieldbuffer(
 516 |                                          WINDOW * win,
 517 |                                          FIELD  * field,
 518 |                                          FIELD_CELL * buf)
 519 |
 520 |   Description   :  Copy the content of the window into the buffer.
 521 |                    The multiple lines of a window are simply
 522 |                    concatenated into the buffer. Pad characters in
 523 |                    the window will be replaced by blanks in the buffer.
 524 |
 525 |   Return Values :  -
 526 +--------------------------------------------------------------------------*/
 527 NCURSES_EXPORT(void)
 528 _nc_get_fieldbuffer(FORM *form, FIELD *field, FIELD_CELL *buf)
 529 {
 530   int pad;
 531   int len = 0;
 532   FIELD_CELL *p;
 533   int row, height;
 534   WINDOW *win;
 535
 536   assert(form && field && buf);
 537
 538   win = form->w;
 539   assert(win);
 540
 541   pad = field->pad;
 542   p = buf;
 543   height = getmaxy(win);
 544
 545   for (row = 0; (row < height) && (row < field->drows); row++)
 546     {
 547       wmove(win, row, 0);
 548       len += myINNSTR(win, p + len, field->dcols);
 549     }
 550   p[len] = myZEROS;
 551
 552   /* replace visual padding character by blanks in buffer */
 553   if (pad != C_BLANK)
 554     {
 555       int i;
 556
 557       for (i = 0; i < len; i++, p++)
 558         {
 559           if ((unsigned long)CharOf(*p) == ChCharOf(pad)
 560 #if USE_WIDEC_SUPPORT
 561               && p->chars[1] == 0
 562 #endif
 563             )
 564             *p = myBLANK;
 565         }
 566     }
 567 }
 568
 569 /*---------------------------------------------------------------------------
 570 |   Facility      :  libnform
 571 |   Function      :  static void Window_To_Buffer(
 572 |                                          FORM   * form,
 573 |                                          FIELD  * field)
 574 |
 575 |   Description   :  Copy the content of the window into the buffer.
 576 |                    The multiple lines of a window are simply
 577 |                    concatenated into the buffer. Pad characters in
 578 |                    the window will be replaced by blanks in the buffer.
 579 |
 580 |   Return Values :  -
 581 +--------------------------------------------------------------------------*/
 582 static void
 583 Window_To_Buffer(FORM *form, FIELD *field)
 584 {
 585   _nc_get_fieldbuffer(form, field, field->buf);
 586 }
 587
 588 /*---------------------------------------------------------------------------
 589 |   Facility      :  libnform
 590 |   Function      :  static void Synchronize_Buffer(FORM * form)
 591 |
 592 |   Description   :  If there was a change, copy the content of the
 593 |                    window into the buffer, so the buffer is synchronized
 594 |                    with the windows content. We have to indicate that the
 595 |                    buffer needs validation due to the change.
 596 |
 597 |   Return Values :  -
 598 +--------------------------------------------------------------------------*/
 599 NCURSES_INLINE static void
 600 Synchronize_Buffer(FORM *form)
 601 {
 602   if (form->status & _WINDOW_MODIFIED)
 603     {
 604       form->status &= ~_WINDOW_MODIFIED;
 605       form->status |= _FCHECK_REQUIRED;
 606       Window_To_Buffer(form, form->current);
 607       wmove(form->w, form->currow, form->curcol);
 608     }
 609 }
 610
 611 /*---------------------------------------------------------------------------
 612 |   Facility      :  libnform
 613 |   Function      :  static bool Field_Grown( FIELD *field, int amount)
 614 |
 615 |   Description   :  This function is called for growable dynamic fields
 616 |                    only. It has to increase the buffers and to allocate
 617 |                    a new window for this field.
 618 |                    This function has the side effect to set a new
 619 |                    field-buffer pointer, the dcols and drows values
 620 |                    as well as a new current Window for the field.
 621 |
 622 |   Return Values :  TRUE     - field successfully increased
 623 |                    FALSE    - there was some error
 624 +--------------------------------------------------------------------------*/
 625 static bool
 626 Field_Grown(FIELD *field, int amount)
 627 {
 628   bool result = FALSE;
 629
 630   if (field && Growable(field))
 631     {
 632       bool single_line_field = Single_Line_Field(field);
 633       int old_buflen = Buffer_Length(field);
 634       int new_buflen;
 635       int old_dcols = field->dcols;
 636       int old_drows = field->drows;
 637       FIELD_CELL *oldbuf = field->buf;
 638       FIELD_CELL *newbuf;
 639
 640       int growth;
 641       FORM *form = field->form;
 642       bool need_visual_update = ((form != (FORM *)0) &&
 643                                  (form->status & _POSTED) &&
 644                                  (form->current == field));
 645
 646       if (need_visual_update)
 647         Synchronize_Buffer(form);
 648
 649       if (single_line_field)
 650         {
 651           growth = field->cols * amount;
 652           if (field->maxgrow)
 653             growth = Minimum(field->maxgrow - field->dcols, growth);
 654           field->dcols += growth;
 655           if (field->dcols == field->maxgrow)
 656             field->status &= ~_MAY_GROW;
 657         }
 658       else
 659         {
 660           growth = (field->rows + field->nrow) * amount;
 661           if (field->maxgrow)
 662             growth = Minimum(field->maxgrow - field->drows, growth);
 663           field->drows += growth;
 664           if (field->drows == field->maxgrow)
 665             field->status &= ~_MAY_GROW;
 666         }
 667       /* drows, dcols changed, so we get really the new buffer length */
 668       new_buflen = Buffer_Length(field);
 669       newbuf = (FIELD_CELL *)malloc(Total_Buffer_Size(field));
 670       if (!newbuf)
 671         {
 672           /* restore to previous state */
 673           field->dcols = old_dcols;
 674           field->drows = old_drows;
 675           if ((single_line_field && (field->dcols != field->maxgrow)) ||
 676               (!single_line_field && (field->drows != field->maxgrow)))
 677             field->status |= _MAY_GROW;
 678         }
 679       else
 680         {
 681           /* Copy all the buffers.  This is the reason why we can't just use
 682            * realloc().
 683            */
 684           int i, j;
 685           FIELD_CELL *old_bp;
 686           FIELD_CELL *new_bp;
 687
 688           result = TRUE;        /* allow sharing of recovery on failure */
 689
 690           T((T_CREATE("fieldcell %p"), (void *)newbuf));
 691           field->buf = newbuf;
 692           for (i = 0; i <= field->nbuf; i++)
 693             {
 694               new_bp = Address_Of_Nth_Buffer(field, i);
 695               old_bp = oldbuf + i * (1 + old_buflen);
 696               for (j = 0; j < old_buflen; ++j)
 697                 new_bp[j] = old_bp[j];
 698               while (j < new_buflen)
 699                 new_bp[j++] = myBLANK;
 700               new_bp[new_buflen] = myZEROS;
 701             }
 702
 703 #if USE_WIDEC_SUPPORT && NCURSES_EXT_FUNCS
 704           if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
 705             result = FALSE;
 706 #endif
 707
 708           if (need_visual_update && result)
 709             {
 710               WINDOW *new_window = newpad(field->drows, field->dcols);
 711
 712               if (new_window != 0)
 713                 {
 714                   assert(form != (FORM *)0);
 715                   if (form->w)
 716                     delwin(form->w);
 717                   form->w = new_window;
 718                   Set_Field_Window_Attributes(field, form->w);
 719                   werase(form->w);
 720                   Buffer_To_Window(field, form->w);
 721                   untouchwin(form->w);
 722                   wmove(form->w, form->currow, form->curcol);
 723                 }
 724               else
 725                 result = FALSE;
 726             }
 727
 728           if (result)
 729             {
 730               free(oldbuf);
 731               /* reflect changes in linked fields */
 732               if (field != field->link)
 733                 {
 734                   FIELD *linked_field;
 735
 736                   for (linked_field = field->link;
 737                        linked_field != field;
 738                        linked_field = linked_field->link)
 739                     {
 740                       linked_field->buf = field->buf;
 741                       linked_field->drows = field->drows;
 742                       linked_field->dcols = field->dcols;
 743                     }
 744                 }
 745             }
 746           else
 747             {
 748               /* restore old state */
 749               field->dcols = old_dcols;
 750               field->drows = old_drows;
 751               field->buf = oldbuf;
 752               if ((single_line_field &&
 753                    (field->dcols != field->maxgrow)) ||
 754                   (!single_line_field &&
 755                    (field->drows != field->maxgrow)))
 756                 field->status |= _MAY_GROW;
 757               free(newbuf);
 758             }
 759         }
 760     }
 761   return (result);
 762 }
 763
 764 #ifdef NCURSES_MOUSE_VERSION
 765 /*---------------------------------------------------------------------------
 766 |   Facility      :  libnform
 767 |   Function      :  int Field_encloses(FIELD *field, int ry, int rx)
 768 |
 769 |   Description   :  Check if the given coordinates lie within the given field.
 770 |
 771 |   Return Values :  E_OK              - success
 772 |                    E_BAD_ARGUMENT    - invalid form pointer
 773 |                    E_SYSTEM_ERROR    - form has no current field or
 774 |                                        field-window
 775 +--------------------------------------------------------------------------*/
 776 static int
 777 Field_encloses(FIELD *field, int ry, int rx)
 778 {
 779   T((T_CALLED("Field_encloses(%p)"), (void *)field));
 780   if (field != 0
 781       && field->frow <= ry
 782       && (field->frow + field->rows) > ry
 783       && field->fcol <= rx
 784       && (field->fcol + field->cols) > rx)
 785     {
 786       RETURN(E_OK);
 787     }
 788   RETURN(E_INVALID_FIELD);
 789 }
 790 #endif
 791
 792 /*---------------------------------------------------------------------------
 793 |   Facility      :  libnform
 794 |   Function      :  int _nc_Position_Form_Cursor(FORM * form)
 795 |
 796 |   Description   :  Position the cursor in the window for the current
 797 |                    field to be in sync. with the currow and curcol
 798 |                    values.
 799 |
 800 |   Return Values :  E_OK              - success
 801 |                    E_BAD_ARGUMENT    - invalid form pointer
 802 |                    E_SYSTEM_ERROR    - form has no current field or
 803 |                                        field-window
 804 +--------------------------------------------------------------------------*/
 805 NCURSES_EXPORT(int)
 806 _nc_Position_Form_Cursor(FORM *form)
 807 {
 808   FIELD *field;
 809   WINDOW *formwin;
 810
 811   if (!form)
 812     return (E_BAD_ARGUMENT);
 813
 814   if (!form->w || !form->current)
 815     return (E_SYSTEM_ERROR);
 816
 817   field = form->current;
 818   formwin = Get_Form_Window(form);
 819
 820   wmove(form->w, form->currow, form->curcol);
 821   if (Has_Invisible_Parts(field))
 822     {
 823       /* in this case fieldwin isn't derived from formwin, so we have
 824          to move the cursor in formwin by hand... */
 825       wmove(formwin,
 826             field->frow + form->currow - form->toprow,
 827             field->fcol + form->curcol - form->begincol);
 828       wcursyncup(formwin);
 829     }
 830   else
 831     wcursyncup(form->w);
 832   return (E_OK);
 833 }
 834
 835 /*---------------------------------------------------------------------------
 836 |   Facility      :  libnform
 837 |   Function      :  int _nc_Refresh_Current_Field(FORM * form)
 838 |
 839 |   Description   :  Propagate the changes in the fields window to the
 840 |                    window of the form.
 841 |
 842 |   Return Values :  E_OK              - on success
 843 |                    E_BAD_ARGUMENT    - invalid form pointer
 844 |                    E_SYSTEM_ERROR    - general error
 845 +--------------------------------------------------------------------------*/
 846 NCURSES_EXPORT(int)
 847 _nc_Refresh_Current_Field(FORM *form)
 848 {
 849   WINDOW *formwin;
 850   FIELD *field;
 851
 852   T((T_CALLED("_nc_Refresh_Current_Field(%p)"), (void *)form));
 853
 854   if (!form)
 855     RETURN(E_BAD_ARGUMENT);
 856
 857   if (!form->w || !form->current)
 858     RETURN(E_SYSTEM_ERROR);
 859
 860   field = form->current;
 861   formwin = Get_Form_Window(form);
 862
 863   if (field->opts & O_PUBLIC)
 864     {
 865       if (Is_Scroll_Field(field))
 866         {
 867           /* Again, in this case the fieldwin isn't derived from formwin,
 868              so we have to perform a copy operation. */
 869           if (Single_Line_Field(field))
 870             {
 871               /* horizontal scrolling */
 872               if (form->curcol < form->begincol)
 873                 form->begincol = form->curcol;
 874               else
 875                 {
 876                   if (form->curcol >= (form->begincol + field->cols))
 877                     form->begincol = form->curcol - field->cols + 1;
 878                 }
 879               copywin(form->w,
 880                       formwin,
 881                       0,
 882                       form->begincol,
 883                       field->frow,
 884                       field->fcol,
 885                       field->frow,
 886                       field->cols + field->fcol - 1,
 887                       0);
 888             }
 889           else
 890             {
 891               /* A multi-line, i.e. vertical scrolling field */
 892               int row_after_bottom, first_modified_row, first_unmodified_row;
 893
 894               if (field->drows > field->rows)
 895                 {
 896                   row_after_bottom = form->toprow + field->rows;
 897                   if (form->currow < form->toprow)
 898                     {
 899                       form->toprow = form->currow;
 900                       field->status |= _NEWTOP;
 901                     }
 902                   if (form->currow >= row_after_bottom)
 903                     {
 904                       form->toprow = form->currow - field->rows + 1;
 905                       field->status |= _NEWTOP;
 906                     }
 907                   if (field->status & _NEWTOP)
 908                     {
 909                       /* means we have to copy whole range */
 910                       first_modified_row = form->toprow;
 911                       first_unmodified_row = first_modified_row + field->rows;
 912                       field->status &= ~_NEWTOP;
 913                     }
 914                   else
 915                     {
 916                       /* we try to optimize : finding the range of touched
 917                          lines */
 918                       first_modified_row = form->toprow;
 919                       while (first_modified_row < row_after_bottom)
 920                         {
 921                           if (is_linetouched(form->w, first_modified_row))
 922                             break;
 923                           first_modified_row++;
 924                         }
 925                       first_unmodified_row = first_modified_row;
 926                       while (first_unmodified_row < row_after_bottom)
 927                         {
 928                           if (!is_linetouched(form->w, first_unmodified_row))
 929                             break;
 930                           first_unmodified_row++;
 931                         }
 932                     }
 933                 }
 934               else
 935                 {
 936                   first_modified_row = form->toprow;
 937                   first_unmodified_row = first_modified_row + field->rows;
 938                 }
 939               if (first_unmodified_row != first_modified_row)
 940                 copywin(form->w,
 941                         formwin,
 942                         first_modified_row,
 943                         0,
 944                         field->frow + first_modified_row - form->toprow,
 945                         field->fcol,
 946                         field->frow + first_unmodified_row - form->toprow - 1,
 947                         field->cols + field->fcol - 1,
 948                         0);
 949             }
 950           wsyncup(formwin);
 951         }
 952       else
 953         {
 954           /* if the field-window is simply a derived window, i.e. contains no
 955            * invisible parts, the whole thing is trivial
 956            */
 957           wsyncup(form->w);
 958         }
 959     }
 960   untouchwin(form->w);
 961   returnCode(_nc_Position_Form_Cursor(form));
 962 }
 963
 964 /*---------------------------------------------------------------------------
 965 |   Facility      :  libnform
 966 |   Function      :  static void Perform_Justification(
 967 |                                        FIELD  * field,
 968 |                                        WINDOW * win)
 969 |
 970 |   Description   :  Output field with requested justification
 971 |
 972 |   Return Values :  -
 973 +--------------------------------------------------------------------------*/
 974 static void
 975 Perform_Justification(FIELD *field, WINDOW *win)
 976 {
 977   FIELD_CELL *bp;
 978   int len;
 979   int col = 0;
 980
 981   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
 982   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
 983
 984   if (len > 0)
 985     {
 986       assert(win && (field->drows == 1) && (field->dcols == field->cols));
 987
 988       switch (field->just)
 989         {
 990         case JUSTIFY_LEFT:
 991           break;
 992         case JUSTIFY_CENTER:
 993           col = (field->cols - len) / 2;
 994           break;
 995         case JUSTIFY_RIGHT:
 996           col = field->cols - len;
 997           break;
 998         default:
 999           break;
1000         }
1001
1002       wmove(win, 0, col);
1003       myADDNSTR(win, bp, len);
1004     }
1005 }
1006
1007 /*---------------------------------------------------------------------------
1008 |   Facility      :  libnform
1009 |   Function      :  static void Undo_Justification(
1010 |                                     FIELD  * field,
1011 |                                     WINDOW * win)
1012 |
1013 |   Description   :  Display field without any justification, i.e.
1014 |                    left justified
1015 |
1016 |   Return Values :  -
1017 +--------------------------------------------------------------------------*/
1018 static void
1019 Undo_Justification(FIELD *field, WINDOW *win)
1020 {
1021   FIELD_CELL *bp;
1022   int len;
1023
1024   bp = Get_Start_Of_Data(field->buf, Buffer_Length(field));
1025   len = (int)(After_End_Of_Data(field->buf, Buffer_Length(field)) - bp);
1026
1027   if (len > 0)
1028     {
1029       assert(win);
1030       wmove(win, 0, 0);
1031       myADDNSTR(win, bp, len);
1032     }
1033 }
1034
1035 /*---------------------------------------------------------------------------
1036 |   Facility      :  libnform
1037 |   Function      :  static bool Check_Char(FORM  *form,
1038 |                                           FIELD *field,
1039 |                                           FIELDTYPE * typ,
1040 |                                           int ch,
1041 |                                           TypeArgument *argp)
1042 |
1043 |   Description   :  Perform a single character check for character ch
1044 |                    according to the fieldtype instance.
1045 |
1046 |   Return Values :  TRUE             - Character is valid
1047 |                    FALSE            - Character is invalid
1048 +--------------------------------------------------------------------------*/
1049 static bool
1050 Check_Char(FORM *form,
1051            FIELD *field,
1052            FIELDTYPE *typ,
1053            int ch,
1054            TypeArgument *argp)
1055 {
1056   if (typ)
1057     {
1058       if (typ->status & _LINKED_TYPE)
1059         {
1060           assert(argp);
1061           return (
1062                    Check_Char(form, field, typ->left, ch, argp->left) ||
1063                    Check_Char(form, field, typ->right, ch, argp->right));
1064         }
1065       else
1066         {
1067 #if NCURSES_INTEROP_FUNCS
1068           if (typ->charcheck.occheck)
1069             {
1070               if (typ->status & _GENERIC)
1071                 return typ->charcheck.gccheck(ch, form, field, (void *)argp);
1072               else
1073                 return typ->charcheck.occheck(ch, (void *)argp);
1074             }
1075 #else
1076           if (typ->ccheck)
1077             return typ->ccheck(ch, (void *)argp);
1078 #endif
1079         }
1080     }
1081   return (!iscntrl(UChar(ch)) ? TRUE : FALSE);
1082 }
1083
1084 /*---------------------------------------------------------------------------
1085 |   Facility      :  libnform
1086 |   Function      :  static int Display_Or_Erase_Field(
1087 |                                           FIELD * field,
1088 |                                           bool bEraseFlag)
1089 |
1090 |   Description   :  Create a subwindow for the field and display the
1091 |                    buffer contents (apply justification if required)
1092 |                    or simply erase the field.
1093 |
1094 |   Return Values :  E_OK           - on success
1095 |                    E_SYSTEM_ERROR - some error (typical no memory)
1096 +--------------------------------------------------------------------------*/
1097 static int
1098 Display_Or_Erase_Field(FIELD *field, bool bEraseFlag)
1099 {
1100   WINDOW *win;
1101   WINDOW *fwin;
1102
1103   if (!field)
1104     return E_SYSTEM_ERROR;
1105
1106   fwin = Get_Form_Window(field->form);
1107   win = derwin(fwin,
1108                field->rows, field->cols, field->frow, field->fcol);
1109
1110   if (!win)
1111     return E_SYSTEM_ERROR;
1112   else
1113     {
1114       if (field->opts & O_VISIBLE)
1115         {
1116           Set_Field_Window_Attributes(field, win);
1117         }
1118       else
1119         {
1120           (void)wattrset(win, WINDOW_ATTRS(fwin));
1121         }
1122       werase(win);
1123     }
1124
1125   if (!bEraseFlag)
1126     {
1127       if (field->opts & O_PUBLIC)
1128         {
1129           if (Justification_Allowed(field))
1130             Perform_Justification(field, win);
1131           else
1132             Buffer_To_Window(field, win);
1133         }
1134       field->status &= ~_NEWTOP;
1135     }
1136   wsyncup(win);
1137   delwin(win);
1138   return E_OK;
1139 }
1140
1141 /* Macros to preset the bEraseFlag */
1142 #define Display_Field(field) Display_Or_Erase_Field(field,FALSE)
1143 #define Erase_Field(field)   Display_Or_Erase_Field(field,TRUE)
1144
1145 /*---------------------------------------------------------------------------
1146 |   Facility      :  libnform
1147 |   Function      :  static int Synchronize_Field(FIELD * field)
1148 |
1149 |   Description   :  Synchronize the windows content with the value in
1150 |                    the buffer.
1151 |
1152 |   Return Values :  E_OK                - success
1153 |                    E_BAD_ARGUMENT      - invalid field pointer
1154 |                    E_SYSTEM_ERROR      - some severe basic error
1155 +--------------------------------------------------------------------------*/
1156 static int
1157 Synchronize_Field(FIELD *field)
1158 {
1159   FORM *form;
1160   int res = E_OK;
1161
1162   if (!field)
1163     return (E_BAD_ARGUMENT);
1164
1165   if (((form = field->form) != (FORM *)0)
1166       && Field_Really_Appears(field))
1167     {
1168       if (field == form->current)
1169         {
1170           form->currow = form->curcol = form->toprow = form->begincol = 0;
1171           werase(form->w);
1172
1173           if ((field->opts & O_PUBLIC) && Justification_Allowed(field))
1174             Undo_Justification(field, form->w);
1175           else
1176             Buffer_To_Window(field, form->w);
1177
1178           field->status |= _NEWTOP;
1179           res = _nc_Refresh_Current_Field(form);
1180         }
1181       else
1182         res = Display_Field(field);
1183     }
1184   field->status |= _CHANGED;
1185   return (res);
1186 }
1187
1188 /*---------------------------------------------------------------------------
1189 |   Facility      :  libnform
1190 |   Function      :  static int Synchronize_Linked_Fields(FIELD * field)
1191 |
1192 |   Description   :  Propagate the Synchronize_Field function to all linked
1193 |                    fields. The first error that occurs in the sequence
1194 |                    of updates is the return value.
1195 |
1196 |   Return Values :  E_OK                - success
1197 |                    E_BAD_ARGUMENT      - invalid field pointer
1198 |                    E_SYSTEM_ERROR      - some severe basic error
1199 +--------------------------------------------------------------------------*/
1200 static int
1201 Synchronize_Linked_Fields(FIELD *field)
1202 {
1203   FIELD *linked_field;
1204   int res = E_OK;
1205   int syncres;
1206
1207   if (!field)
1208     return (E_BAD_ARGUMENT);
1209
1210   if (!field->link)
1211     return (E_SYSTEM_ERROR);
1212
1213   for (linked_field = field->link;
1214        linked_field != field;
1215        linked_field = linked_field->link)
1216     {
1217       if (((syncres = Synchronize_Field(linked_field)) != E_OK) &&
1218           (res == E_OK))
1219         res = syncres;
1220     }
1221   return (res);
1222 }
1223
1224 /*---------------------------------------------------------------------------
1225 |   Facility      :  libnform
1226 |   Function      :  int _nc_Synchronize_Attributes(FIELD * field)
1227 |
1228 |   Description   :  If a fields visual attributes have changed, this
1229 |                    routine is called to propagate those changes to the
1230 |                    screen.
1231 |
1232 |   Return Values :  E_OK             - success
1233 |                    E_BAD_ARGUMENT   - invalid field pointer
1234 |                    E_SYSTEM_ERROR   - some severe basic error
1235 +--------------------------------------------------------------------------*/
1236 NCURSES_EXPORT(int)
1237 _nc_Synchronize_Attributes(FIELD *field)
1238 {
1239   FORM *form;
1240   int res = E_OK;
1241   WINDOW *formwin;
1242
1243   T((T_CALLED("_nc_Synchronize_Attributes(%p)"), (void *)field));
1244
1245   if (!field)
1246     returnCode(E_BAD_ARGUMENT);
1247
1248   CHECKPOS(field->form);
1249   if (((form = field->form) != (FORM *)0)
1250       && Field_Really_Appears(field))
1251     {
1252       if (form->current == field)
1253         {
1254           Synchronize_Buffer(form);
1255           Set_Field_Window_Attributes(field, form->w);
1256           werase(form->w);
1257           wmove(form->w, form->currow, form->curcol);
1258
1259           if (field->opts & O_PUBLIC)
1260             {
1261               if (Justification_Allowed(field))
1262                 Undo_Justification(field, form->w);
1263               else
1264                 Buffer_To_Window(field, form->w);
1265             }
1266           else
1267             {
1268               formwin = Get_Form_Window(form);
1269               copywin(form->w, formwin,
1270                       0, 0,
1271                       field->frow, field->fcol,
1272                       field->rows - 1, field->cols - 1, 0);
1273               wsyncup(formwin);
1274               Buffer_To_Window(field, form->w);
1275               field->status |= _NEWTOP;         /* fake refresh to paint all */
1276               _nc_Refresh_Current_Field(form);
1277             }
1278         }
1279       else
1280         {
1281           res = Display_Field(field);
1282         }
1283     }
1284   CHECKPOS(form);
1285   returnCode(res);
1286 }
1287
1288 /*---------------------------------------------------------------------------
1289 |   Facility      :  libnform
1290 |   Function      :  int _nc_Synchronize_Options(FIELD * field,
1291 |                                                Field_Options newopts)
1292 |
1293 |   Description   :  If a fields options have changed, this routine is
1294 |                    called to propagate these changes to the screen and
1295 |                    to really change the behavior of the field.
1296 |
1297 |   Return Values :  E_OK                - success
1298 |                    E_BAD_ARGUMENT      - invalid field pointer
1299 |                    E_CURRENT           - field is the current one
1300 |                    E_SYSTEM_ERROR      - some severe basic error
1301 +--------------------------------------------------------------------------*/
1302 NCURSES_EXPORT(int)
1303 _nc_Synchronize_Options(FIELD *field, Field_Options newopts)
1304 {
1305   Field_Options oldopts;
1306   Field_Options changed_opts;
1307   FORM *form;
1308   int res = E_OK;
1309
1310   T((T_CALLED("_nc_Synchronize_Options(%p,%#x)"), (void *)field, newopts));
1311
1312   if (!field)
1313     returnCode(E_BAD_ARGUMENT);
1314
1315   oldopts = field->opts;
1316   changed_opts = oldopts ^ newopts;
1317   field->opts = newopts;
1318   form = field->form;
1319
1320   if (form)
1321     {
1322       if (form->status & _POSTED)
1323         {
1324           if (form->current == field)
1325             {
1326               field->opts = oldopts;
1327               returnCode(E_CURRENT);
1328             }
1329           if ((form->curpage == field->page))
1330             {
1331               if (changed_opts & O_VISIBLE)
1332                 {
1333                   if (newopts & O_VISIBLE)
1334                     res = Display_Field(field);
1335                   else
1336                     res = Erase_Field(field);
1337                 }
1338               else
1339                 {
1340                   if ((changed_opts & O_PUBLIC) &&
1341                       (newopts & O_VISIBLE))
1342                     res = Display_Field(field);
1343                 }
1344             }
1345         }
1346     }
1347
1348   if (changed_opts & O_STATIC)
1349     {
1350       bool single_line_field = Single_Line_Field(field);
1351       int res2 = E_OK;
1352
1353       if (newopts & O_STATIC)
1354         {
1355           /* the field becomes now static */
1356           field->status &= ~_MAY_GROW;
1357           /* if actually we have no hidden columns, justification may
1358              occur again */
1359           if (single_line_field &&
1360               (field->cols == field->dcols) &&
1361               (field->just != NO_JUSTIFICATION) &&
1362               Field_Really_Appears(field))
1363             {
1364               res2 = Display_Field(field);
1365             }
1366         }
1367       else
1368         {
1369           /* field is no longer static */
1370           if ((field->maxgrow == 0) ||
1371               (single_line_field && (field->dcols < field->maxgrow)) ||
1372               (!single_line_field && (field->drows < field->maxgrow)))
1373             {
1374               field->status |= _MAY_GROW;
1375               /* a field with justification now changes its behavior,
1376                  so we must redisplay it */
1377               if (single_line_field &&
1378                   (field->just != NO_JUSTIFICATION) &&
1379                   Field_Really_Appears(field))
1380                 {
1381                   res2 = Display_Field(field);
1382                 }
1383             }
1384         }
1385       if (res2 != E_OK)
1386         res = res2;
1387     }
1388
1389   returnCode(res);
1390 }
1391
1392 /*---------------------------------------------------------------------------
1393 |   Facility      :  libnform
1394 |   Function      :  int _nc_Set_Current_Field(FORM  * form,
1395 |                                              FIELD * newfield)
1396 |
1397 |   Description   :  Make the newfield the new current field.
1398 |
1399 |   Return Values :  E_OK              - success
1400 |                    E_BAD_ARGUMENT    - invalid form or field pointer
1401 |                    E_SYSTEM_ERROR    - some severe basic error
1402 |                    E_NOT_CONNECTED   - no fields are connected to the form
1403 +--------------------------------------------------------------------------*/
1404 NCURSES_EXPORT(int)
1405 _nc_Set_Current_Field(FORM *form, FIELD *newfield)
1406 {
1407   FIELD *field;
1408   WINDOW *new_window;
1409
1410   T((T_CALLED("_nc_Set_Current_Field(%p,%p)"), (void *)form, (void *)newfield));
1411
1412   if (!form || !newfield || !form->current || (newfield->form != form))
1413     returnCode(E_BAD_ARGUMENT);
1414
1415   if ((form->status & _IN_DRIVER))
1416     returnCode(E_BAD_STATE);
1417
1418   if (!(form->field))
1419     returnCode(E_NOT_CONNECTED);
1420
1421   field = form->current;
1422
1423   if ((field != newfield) ||
1424       !(form->status & _POSTED))
1425     {
1426       if ((form->w) &&
1427           (field->opts & O_VISIBLE) &&
1428           (field->form->curpage == field->page))
1429         {
1430           _nc_Refresh_Current_Field(form);
1431           if (field->opts & O_PUBLIC)
1432             {
1433               if (field->drows > field->rows)
1434                 {
1435                   if (form->toprow == 0)
1436                     field->status &= ~_NEWTOP;
1437                   else
1438                     field->status |= _NEWTOP;
1439                 }
1440               else
1441                 {
1442                   if (Justification_Allowed(field))
1443                     {
1444                       Window_To_Buffer(form, field);
1445                       werase(form->w);
1446                       Perform_Justification(field, form->w);
1447                       wsyncup(form->w);
1448                     }
1449                 }
1450             }
1451           delwin(form->w);
1452           form->w = (WINDOW *)0;
1453         }
1454
1455       field = newfield;
1456
1457       if (Has_Invisible_Parts(field))
1458         new_window = newpad(field->drows, field->dcols);
1459       else
1460         new_window = derwin(Get_Form_Window(form),
1461                             field->rows, field->cols, field->frow, field->fcol);
1462
1463       if (!new_window)
1464         returnCode(E_SYSTEM_ERROR);
1465
1466       form->current = field;
1467
1468       if (form->w)
1469         delwin(form->w);
1470       form->w = new_window;
1471
1472       form->status &= ~_WINDOW_MODIFIED;
1473       Set_Field_Window_Attributes(field, form->w);
1474
1475       if (Has_Invisible_Parts(field))
1476         {
1477           werase(form->w);
1478           Buffer_To_Window(field, form->w);
1479         }
1480       else
1481         {
1482           if (Justification_Allowed(field))
1483             {
1484               werase(form->w);
1485               Undo_Justification(field, form->w);
1486               wsyncup(form->w);
1487             }
1488         }
1489
1490       untouchwin(form->w);
1491     }
1492
1493   form->currow = form->curcol = form->toprow = form->begincol = 0;
1494   returnCode(E_OK);
1495 }
1496
1497 /*----------------------------------------------------------------------------
1498   Intra-Field Navigation routines
1499   --------------------------------------------------------------------------*/
1500
1501 /*---------------------------------------------------------------------------
1502 |   Facility      :  libnform
1503 |   Function      :  static int IFN_Next_Character(FORM * form)
1504 |
1505 |   Description   :  Move to the next character in the field. In a multi-line
1506 |                    field this wraps at the end of the line.
1507 |
1508 |   Return Values :  E_OK                - success
1509 |                    E_REQUEST_DENIED    - at the rightmost position
1510 +--------------------------------------------------------------------------*/
1511 static int
1512 IFN_Next_Character(FORM *form)
1513 {
1514   FIELD *field = form->current;
1515   int step = myWCWIDTH(form->w, form->currow, form->curcol);
1516
1517   T((T_CALLED("IFN_Next_Character(%p)"), (void *)form));
1518   if ((form->curcol += step) == field->dcols)
1519     {
1520       if ((++(form->currow)) == field->drows)
1521         {
1522 #if GROW_IF_NAVIGATE
1523           if (!Single_Line_Field(field) && Field_Grown(field, 1))
1524             {
1525               form->curcol = 0;
1526               returnCode(E_OK);
1527             }
1528 #endif
1529           form->currow--;
1530 #if GROW_IF_NAVIGATE
1531           if (Single_Line_Field(field) && Field_Grown(field, 1))
1532             returnCode(E_OK);
1533 #endif
1534           form->curcol -= step;
1535           returnCode(E_REQUEST_DENIED);
1536         }
1537       form->curcol = 0;
1538     }
1539   returnCode(E_OK);
1540 }
1541
1542 /*---------------------------------------------------------------------------
1543 |   Facility      :  libnform
1544 |   Function      :  static int IFN_Previous_Character(FORM * form)
1545 |
1546 |   Description   :  Move to the previous character in the field. In a
1547 |                    multi-line field this wraps and the beginning of the
1548 |                    line.
1549 |
1550 |   Return Values :  E_OK                - success
1551 |                    E_REQUEST_DENIED    - at the leftmost position
1552 +--------------------------------------------------------------------------*/
1553 static int
1554 IFN_Previous_Character(FORM *form)
1555 {
1556   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1557   int oldcol = form->curcol;
1558
1559   T((T_CALLED("IFN_Previous_Character(%p)"), (void *)form));
1560   if ((form->curcol -= amount) < 0)
1561     {
1562       if ((--(form->currow)) < 0)
1563         {
1564           form->currow++;
1565           form->curcol = oldcol;
1566           returnCode(E_REQUEST_DENIED);
1567         }
1568       form->curcol = form->current->dcols - 1;
1569     }
1570   returnCode(E_OK);
1571 }
1572
1573 /*---------------------------------------------------------------------------
1574 |   Facility      :  libnform
1575 |   Function      :  static int IFN_Next_Line(FORM * form)
1576 |
1577 |   Description   :  Move to the beginning of the next line in the field
1578 |
1579 |   Return Values :  E_OK                - success
1580 |                    E_REQUEST_DENIED    - at the last line
1581 +--------------------------------------------------------------------------*/
1582 static int
1583 IFN_Next_Line(FORM *form)
1584 {
1585   FIELD *field = form->current;
1586
1587   T((T_CALLED("IFN_Next_Line(%p)"), (void *)form));
1588   if ((++(form->currow)) == field->drows)
1589     {
1590 #if GROW_IF_NAVIGATE
1591       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1592         returnCode(E_OK);
1593 #endif
1594       form->currow--;
1595       returnCode(E_REQUEST_DENIED);
1596     }
1597   form->curcol = 0;
1598   returnCode(E_OK);
1599 }
1600
1601 /*---------------------------------------------------------------------------
1602 |   Facility      :  libnform
1603 |   Function      :  static int IFN_Previous_Line(FORM * form)
1604 |
1605 |   Description   :  Move to the beginning of the previous line in the field
1606 |
1607 |   Return Values :  E_OK                - success
1608 |                    E_REQUEST_DENIED    - at the first line
1609 +--------------------------------------------------------------------------*/
1610 static int
1611 IFN_Previous_Line(FORM *form)
1612 {
1613   T((T_CALLED("IFN_Previous_Line(%p)"), (void *)form));
1614   if ((--(form->currow)) < 0)
1615     {
1616       form->currow++;
1617       returnCode(E_REQUEST_DENIED);
1618     }
1619   form->curcol = 0;
1620   returnCode(E_OK);
1621 }
1622
1623 /*---------------------------------------------------------------------------
1624 |   Facility      :  libnform
1625 |   Function      :  static int IFN_Next_Word(FORM * form)
1626 |
1627 |   Description   :  Move to the beginning of the next word in the field.
1628 |
1629 |   Return Values :  E_OK             - success
1630 |                    E_REQUEST_DENIED - there is no next word
1631 +--------------------------------------------------------------------------*/
1632 static int
1633 IFN_Next_Word(FORM *form)
1634 {
1635   FIELD *field = form->current;
1636   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1637   FIELD_CELL *s;
1638   FIELD_CELL *t;
1639
1640   T((T_CALLED("IFN_Next_Word(%p)"), (void *)form));
1641
1642   /* We really need access to the data, so we have to synchronize */
1643   Synchronize_Buffer(form);
1644
1645   /* Go to the first whitespace after the current position (including
1646      current position). This is then the starting point to look for the
1647      next non-blank data */
1648   s = Get_First_Whitespace_Character(bp, Buffer_Length(field) -
1649                                      (int)(bp - field->buf));
1650
1651   /* Find the start of the next word */
1652   t = Get_Start_Of_Data(s, Buffer_Length(field) -
1653                         (int)(s - field->buf));
1654 #if !FRIENDLY_PREV_NEXT_WORD
1655   if (s == t)
1656     returnCode(E_REQUEST_DENIED);
1657   else
1658 #endif
1659     {
1660       Adjust_Cursor_Position(form, t);
1661       returnCode(E_OK);
1662     }
1663 }
1664
1665 /*---------------------------------------------------------------------------
1666 |   Facility      :  libnform
1667 |   Function      :  static int IFN_Previous_Word(FORM * form)
1668 |
1669 |   Description   :  Move to the beginning of the previous word in the field.
1670 |
1671 |   Return Values :  E_OK             - success
1672 |                    E_REQUEST_DENIED - there is no previous word
1673 +--------------------------------------------------------------------------*/
1674 static int
1675 IFN_Previous_Word(FORM *form)
1676 {
1677   FIELD *field = form->current;
1678   FIELD_CELL *bp = Address_Of_Current_Position_In_Buffer(form);
1679   FIELD_CELL *s;
1680   FIELD_CELL *t;
1681   bool again = FALSE;
1682
1683   T((T_CALLED("IFN_Previous_Word(%p)"), (void *)form));
1684
1685   /* We really need access to the data, so we have to synchronize */
1686   Synchronize_Buffer(form);
1687
1688   s = After_End_Of_Data(field->buf, (int)(bp - field->buf));
1689   /* s points now right after the last non-blank in the buffer before bp.
1690      If bp was in a word, s equals bp. In this case we must find the last
1691      whitespace in the buffer before bp and repeat the game to really find
1692      the previous word! */
1693   if (s == bp)
1694     again = TRUE;
1695
1696   /* And next call now goes backward to look for the last whitespace
1697      before that, pointing right after this, so it points to the begin
1698      of the previous word.
1699    */
1700   t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1701 #if !FRIENDLY_PREV_NEXT_WORD
1702   if (s == t)
1703     returnCode(E_REQUEST_DENIED);
1704 #endif
1705   if (again)
1706     {
1707       /* and do it again, replacing bp by t */
1708       s = After_End_Of_Data(field->buf, (int)(t - field->buf));
1709       t = After_Last_Whitespace_Character(field->buf, (int)(s - field->buf));
1710 #if !FRIENDLY_PREV_NEXT_WORD
1711       if (s == t)
1712         returnCode(E_REQUEST_DENIED);
1713 #endif
1714     }
1715   Adjust_Cursor_Position(form, t);
1716   returnCode(E_OK);
1717 }
1718
1719 /*---------------------------------------------------------------------------
1720 |   Facility      :  libnform
1721 |   Function      :  static int IFN_Beginning_Of_Field(FORM * form)
1722 |
1723 |   Description   :  Place the cursor at the first non-pad character in
1724 |                    the field.
1725 |
1726 |   Return Values :  E_OK             - success
1727 +--------------------------------------------------------------------------*/
1728 static int
1729 IFN_Beginning_Of_Field(FORM *form)
1730 {
1731   FIELD *field = form->current;
1732
1733   T((T_CALLED("IFN_Beginning_Of_Field(%p)"), (void *)form));
1734   Synchronize_Buffer(form);
1735   Adjust_Cursor_Position(form,
1736                          Get_Start_Of_Data(field->buf, Buffer_Length(field)));
1737   returnCode(E_OK);
1738 }
1739
1740 /*---------------------------------------------------------------------------
1741 |   Facility      :  libnform
1742 |   Function      :  static int IFN_End_Of_Field(FORM * form)
1743 |
1744 |   Description   :  Place the cursor after the last non-pad character in
1745 |                    the field. If the field occupies the last position in
1746 |                    the buffer, the cursor is positioned on the last
1747 |                    character.
1748 |
1749 |   Return Values :  E_OK              - success
1750 +--------------------------------------------------------------------------*/
1751 static int
1752 IFN_End_Of_Field(FORM *form)
1753 {
1754   FIELD *field = form->current;
1755   FIELD_CELL *pos;
1756
1757   T((T_CALLED("IFN_End_Of_Field(%p)"), (void *)form));
1758   Synchronize_Buffer(form);
1759   pos = After_End_Of_Data(field->buf, Buffer_Length(field));
1760   if (pos == (field->buf + Buffer_Length(field)))
1761     pos--;
1762   Adjust_Cursor_Position(form, pos);
1763   returnCode(E_OK);
1764 }
1765
1766 /*---------------------------------------------------------------------------
1767 |   Facility      :  libnform
1768 |   Function      :  static int IFN_Beginning_Of_Line(FORM * form)
1769 |
1770 |   Description   :  Place the cursor on the first non-pad character in
1771 |                    the current line of the field.
1772 |
1773 |   Return Values :  E_OK         - success
1774 +--------------------------------------------------------------------------*/
1775 static int
1776 IFN_Beginning_Of_Line(FORM *form)
1777 {
1778   FIELD *field = form->current;
1779
1780   T((T_CALLED("IFN_Beginning_Of_Line(%p)"), (void *)form));
1781   Synchronize_Buffer(form);
1782   Adjust_Cursor_Position(form,
1783                          Get_Start_Of_Data(Address_Of_Current_Row_In_Buffer(form),
1784                                            field->dcols));
1785   returnCode(E_OK);
1786 }
1787
1788 /*---------------------------------------------------------------------------
1789 |   Facility      :  libnform
1790 |   Function      :  static int IFN_End_Of_Line(FORM * form)
1791 |
1792 |   Description   :  Place the cursor after the last non-pad character in the
1793 |                    current line of the field. If the field occupies the
1794 |                    last column in the line, the cursor is positioned on the
1795 |                    last character of the line.
1796 |
1797 |   Return Values :  E_OK        - success
1798 +--------------------------------------------------------------------------*/
1799 static int
1800 IFN_End_Of_Line(FORM *form)
1801 {
1802   FIELD *field = form->current;
1803   FIELD_CELL *pos;
1804   FIELD_CELL *bp;
1805
1806   T((T_CALLED("IFN_End_Of_Line(%p)"), (void *)form));
1807   Synchronize_Buffer(form);
1808   bp = Address_Of_Current_Row_In_Buffer(form);
1809   pos = After_End_Of_Data(bp, field->dcols);
1810   if (pos == (bp + field->dcols))
1811     pos--;
1812   Adjust_Cursor_Position(form, pos);
1813   returnCode(E_OK);
1814 }
1815
1816 /*---------------------------------------------------------------------------
1817 |   Facility      :  libnform
1818 |   Function      :  static int IFN_Left_Character(FORM * form)
1819 |
1820 |   Description   :  Move one character to the left in the current line.
1821 |                    This doesn't cycle.
1822 |
1823 |   Return Values :  E_OK             - success
1824 |                    E_REQUEST_DENIED - already in first column
1825 +--------------------------------------------------------------------------*/
1826 static int
1827 IFN_Left_Character(FORM *form)
1828 {
1829   int amount = myWCWIDTH(form->w, form->currow, form->curcol - 1);
1830   int oldcol = form->curcol;
1831
1832   T((T_CALLED("IFN_Left_Character(%p)"), (void *)form));
1833   if ((form->curcol -= amount) < 0)
1834     {
1835       form->curcol = oldcol;
1836       returnCode(E_REQUEST_DENIED);
1837     }
1838   returnCode(E_OK);
1839 }
1840
1841 /*---------------------------------------------------------------------------
1842 |   Facility      :  libnform
1843 |   Function      :  static int IFN_Right_Character(FORM * form)
1844 |
1845 |   Description   :  Move one character to the right in the current line.
1846 |                    This doesn't cycle.
1847 |
1848 |   Return Values :  E_OK              - success
1849 |                    E_REQUEST_DENIED  - already in last column
1850 +--------------------------------------------------------------------------*/
1851 static int
1852 IFN_Right_Character(FORM *form)
1853 {
1854   int amount = myWCWIDTH(form->w, form->currow, form->curcol);
1855   int oldcol = form->curcol;
1856
1857   T((T_CALLED("IFN_Right_Character(%p)"), (void *)form));
1858   if ((form->curcol += amount) >= form->current->dcols)
1859     {
1860 #if GROW_IF_NAVIGATE
1861       FIELD *field = form->current;
1862
1863       if (Single_Line_Field(field) && Field_Grown(field, 1))
1864         returnCode(E_OK);
1865 #endif
1866       form->curcol = oldcol;
1867       returnCode(E_REQUEST_DENIED);
1868     }
1869   returnCode(E_OK);
1870 }
1871
1872 /*---------------------------------------------------------------------------
1873 |   Facility      :  libnform
1874 |   Function      :  static int IFN_Up_Character(FORM * form)
1875 |
1876 |   Description   :  Move one line up. This doesn't cycle through the lines
1877 |                    of the field.
1878 |
1879 |   Return Values :  E_OK              - success
1880 |                    E_REQUEST_DENIED  - already in last column
1881 +--------------------------------------------------------------------------*/
1882 static int
1883 IFN_Up_Character(FORM *form)
1884 {
1885   T((T_CALLED("IFN_Up_Character(%p)"), (void *)form));
1886   if ((--(form->currow)) < 0)
1887     {
1888       form->currow++;
1889       returnCode(E_REQUEST_DENIED);
1890     }
1891   returnCode(E_OK);
1892 }
1893
1894 /*---------------------------------------------------------------------------
1895 |   Facility      :  libnform
1896 |   Function      :  static int IFN_Down_Character(FORM * form)
1897 |
1898 |   Description   :  Move one line down. This doesn't cycle through the
1899 |                    lines of the field.
1900 |
1901 |   Return Values :  E_OK              - success
1902 |                    E_REQUEST_DENIED  - already in last column
1903 +--------------------------------------------------------------------------*/
1904 static int
1905 IFN_Down_Character(FORM *form)
1906 {
1907   FIELD *field = form->current;
1908
1909   T((T_CALLED("IFN_Down_Character(%p)"), (void *)form));
1910   if ((++(form->currow)) == field->drows)
1911     {
1912 #if GROW_IF_NAVIGATE
1913       if (!Single_Line_Field(field) && Field_Grown(field, 1))
1914         returnCode(E_OK);
1915 #endif
1916       --(form->currow);
1917       returnCode(E_REQUEST_DENIED);
1918     }
1919   returnCode(E_OK);
1920 }
1921 /*----------------------------------------------------------------------------
1922   END of Intra-Field Navigation routines
1923   --------------------------------------------------------------------------*/
1924
1925 /*----------------------------------------------------------------------------
1926   Vertical scrolling helper routines
1927   --------------------------------------------------------------------------*/
1928
1929 /*---------------------------------------------------------------------------
1930 |   Facility      :  libnform
1931 |   Function      :  static int VSC_Generic(FORM *form, int nlines)
1932 |
1933 |   Description   :  Scroll multi-line field forward (nlines>0) or
1934 |                    backward (nlines<0) this many lines.
1935 |
1936 |   Return Values :  E_OK              - success
1937 |                    E_REQUEST_DENIED  - can't scroll
1938 +--------------------------------------------------------------------------*/
1939 static int
1940 VSC_Generic(FORM *form, int nlines)
1941 {
1942   FIELD *field = form->current;
1943   int res = E_REQUEST_DENIED;
1944   int rows_to_go = (nlines > 0 ? nlines : -nlines);
1945
1946   if (nlines > 0)
1947     {
1948       if ((rows_to_go + form->toprow) > (field->drows - field->rows))
1949         rows_to_go = (field->drows - field->rows - form->toprow);
1950
1951       if (rows_to_go > 0)
1952         {
1953           form->currow += rows_to_go;
1954           form->toprow += rows_to_go;
1955           res = E_OK;
1956         }
1957     }
1958   else
1959     {
1960       if (rows_to_go > form->toprow)
1961         rows_to_go = form->toprow;
1962
1963       if (rows_to_go > 0)
1964         {
1965           form->currow -= rows_to_go;
1966           form->toprow -= rows_to_go;
1967           res = E_OK;
1968         }
1969     }
1970   return (res);
1971 }
1972 /*----------------------------------------------------------------------------
1973   End of Vertical scrolling helper routines
1974   --------------------------------------------------------------------------*/
1975
1976 /*----------------------------------------------------------------------------
1977   Vertical scrolling routines
1978   --------------------------------------------------------------------------*/
1979
1980 /*---------------------------------------------------------------------------
1981 |   Facility      :  libnform
1982 |   Function      :  static int Vertical_Scrolling(
1983 |                                           int (* const fct) (FORM *),
1984 |                                           FORM * form)
1985 |
1986 |   Description   :  Performs the generic vertical scrolling routines.
1987 |                    This has to check for a multi-line field and to set
1988 |                    the _NEWTOP flag if scrolling really occurred.
1989 |
1990 |   Return Values :  Propagated error code from low-level driver calls
1991 +--------------------------------------------------------------------------*/
1992 static int
1993 Vertical_Scrolling(int (*const fct) (FORM *), FORM *form)
1994 {
1995   int res = E_REQUEST_DENIED;
1996
1997   if (!Single_Line_Field(form->current))
1998     {
1999       res = fct(form);
2000       if (res == E_OK)
2001         form->current->status |= _NEWTOP;
2002     }
2003   return (res);
2004 }
2005
2006 /*---------------------------------------------------------------------------
2007 |   Facility      :  libnform
2008 |   Function      :  static int VSC_Scroll_Line_Forward(FORM * form)
2009 |
2010 |   Description   :  Scroll multi-line field forward a line
2011 |
2012 |   Return Values :  E_OK                - success
2013 |                    E_REQUEST_DENIED    - no data ahead
2014 +--------------------------------------------------------------------------*/
2015 static int
2016 VSC_Scroll_Line_Forward(FORM *form)
2017 {
2018   T((T_CALLED("VSC_Scroll_Line_Forward(%p)"), (void *)form));
2019   returnCode(VSC_Generic(form, 1));
2020 }
2021
2022 /*---------------------------------------------------------------------------
2023 |   Facility      :  libnform
2024 |   Function      :  static int VSC_Scroll_Line_Backward(FORM * form)
2025 |
2026 |   Description   :  Scroll multi-line field backward a line
2027 |
2028 |   Return Values :  E_OK                - success
2029 |                    E_REQUEST_DENIED    - no data behind
2030 +--------------------------------------------------------------------------*/
2031 static int
2032 VSC_Scroll_Line_Backward(FORM *form)
2033 {
2034   T((T_CALLED("VSC_Scroll_Line_Backward(%p)"), (void *)form));
2035   returnCode(VSC_Generic(form, -1));
2036 }
2037
2038 /*---------------------------------------------------------------------------
2039 |   Facility      :  libnform
2040 |   Function      :  static int VSC_Scroll_Page_Forward(FORM * form)
2041 |
2042 |   Description   :  Scroll a multi-line field forward a page
2043 |
2044 |   Return Values :  E_OK              - success
2045 |                    E_REQUEST_DENIED  - no data ahead
2046 +--------------------------------------------------------------------------*/
2047 static int
2048 VSC_Scroll_Page_Forward(FORM *form)
2049 {
2050   T((T_CALLED("VSC_Scroll_Page_Forward(%p)"), (void *)form));
2051   returnCode(VSC_Generic(form, form->current->rows));
2052 }
2053
2054 /*---------------------------------------------------------------------------
2055 |   Facility      :  libnform
2056 |   Function      :  static int VSC_Scroll_Half_Page_Forward(FORM * form)
2057 |
2058 |   Description   :  Scroll a multi-line field forward half a page
2059 |
2060 |   Return Values :  E_OK              - success
2061 |                    E_REQUEST_DENIED  - no data ahead
2062 +--------------------------------------------------------------------------*/
2063 static int
2064 VSC_Scroll_Half_Page_Forward(FORM *form)
2065 {
2066   T((T_CALLED("VSC_Scroll_Half_Page_Forward(%p)"), (void *)form));
2067   returnCode(VSC_Generic(form, (form->current->rows + 1) / 2));
2068 }
2069
2070 /*---------------------------------------------------------------------------
2071 |   Facility      :  libnform
2072 |   Function      :  static int VSC_Scroll_Page_Backward(FORM * form)
2073 |
2074 |   Description   :  Scroll a multi-line field backward a page
2075 |
2076 |   Return Values :  E_OK              - success
2077 |                    E_REQUEST_DENIED  - no data behind
2078 +--------------------------------------------------------------------------*/
2079 static int
2080 VSC_Scroll_Page_Backward(FORM *form)
2081 {
2082   T((T_CALLED("VSC_Scroll_Page_Backward(%p)"), (void *)form));
2083   returnCode(VSC_Generic(form, -(form->current->rows)));
2084 }
2085
2086 /*---------------------------------------------------------------------------
2087 |   Facility      :  libnform
2088 |   Function      :  static int VSC_Scroll_Half_Page_Backward(FORM * form)
2089 |
2090 |   Description   :  Scroll a multi-line field backward half a page
2091 |
2092 |   Return Values :  E_OK              - success
2093 |                    E_REQUEST_DENIED  - no data behind
2094 +--------------------------------------------------------------------------*/
2095 static int
2096 VSC_Scroll_Half_Page_Backward(FORM *form)
2097 {
2098   T((T_CALLED("VSC_Scroll_Half_Page_Backward(%p)"), (void *)form));
2099   returnCode(VSC_Generic(form, -((form->current->rows + 1) / 2)));
2100 }
2101 /*----------------------------------------------------------------------------
2102   End of Vertical scrolling routines
2103   --------------------------------------------------------------------------*/
2104
2105 /*----------------------------------------------------------------------------
2106   Horizontal scrolling helper routines
2107   --------------------------------------------------------------------------*/
2108
2109 /*---------------------------------------------------------------------------
2110 |   Facility      :  libnform
2111 |   Function      :  static int HSC_Generic(FORM *form, int ncolumns)
2112 |
2113 |   Description   :  Scroll single-line field forward (ncolumns>0) or
2114 |                    backward (ncolumns<0) this many columns.
2115 |
2116 |   Return Values :  E_OK              - success
2117 |                    E_REQUEST_DENIED  - can't scroll
2118 +--------------------------------------------------------------------------*/
2119 static int
2120 HSC_Generic(FORM *form, int ncolumns)
2121 {
2122   FIELD *field = form->current;
2123   int res = E_REQUEST_DENIED;
2124   int cols_to_go = (ncolumns > 0 ? ncolumns : -ncolumns);
2125
2126   if (ncolumns > 0)
2127     {
2128       if ((cols_to_go + form->begincol) > (field->dcols - field->cols))
2129         cols_to_go = field->dcols - field->cols - form->begincol;
2130
2131       if (cols_to_go > 0)
2132         {
2133           form->curcol += cols_to_go;
2134           form->begincol += cols_to_go;
2135           res = E_OK;
2136         }
2137     }
2138   else
2139     {
2140       if (cols_to_go > form->begincol)
2141         cols_to_go = form->begincol;
2142
2143       if (cols_to_go > 0)
2144         {
2145           form->curcol -= cols_to_go;
2146           form->begincol -= cols_to_go;
2147           res = E_OK;
2148         }
2149     }
2150   return (res);
2151 }
2152 /*----------------------------------------------------------------------------
2153   End of Horizontal scrolling helper routines
2154   --------------------------------------------------------------------------*/
2155
2156 /*----------------------------------------------------------------------------
2157   Horizontal scrolling routines
2158   --------------------------------------------------------------------------*/
2159
2160 /*---------------------------------------------------------------------------
2161 |   Facility      :  libnform
2162 |   Function      :  static int Horizontal_Scrolling(
2163 |                                          int (* const fct) (FORM *),
2164 |                                          FORM * form)
2165 |
2166 |   Description   :  Performs the generic horizontal scrolling routines.
2167 |                    This has to check for a single-line field.
2168 |
2169 |   Return Values :  Propagated error code from low-level driver calls
2170 +--------------------------------------------------------------------------*/
2171 static int
2172 Horizontal_Scrolling(int (*const fct) (FORM *), FORM *form)
2173 {
2174   if (Single_Line_Field(form->current))
2175     return fct(form);
2176   else
2177     return (E_REQUEST_DENIED);
2178 }
2179
2180 /*---------------------------------------------------------------------------
2181 |   Facility      :  libnform
2182 |   Function      :  static int HSC_Scroll_Char_Forward(FORM * form)
2183 |
2184 |   Description   :  Scroll single-line field forward a character
2185 |
2186 |   Return Values :  E_OK                - success
2187 |                    E_REQUEST_DENIED    - no data ahead
2188 +--------------------------------------------------------------------------*/
2189 static int
2190 HSC_Scroll_Char_Forward(FORM *form)
2191 {
2192   T((T_CALLED("HSC_Scroll_Char_Forward(%p)"), (void *)form));
2193   returnCode(HSC_Generic(form, 1));
2194 }
2195
2196 /*---------------------------------------------------------------------------
2197 |   Facility      :  libnform
2198 |   Function      :  static int HSC_Scroll_Char_Backward(FORM * form)
2199 |
2200 |   Description   :  Scroll single-line field backward a character
2201 |
2202 |   Return Values :  E_OK                - success
2203 |                    E_REQUEST_DENIED    - no data behind
2204 +--------------------------------------------------------------------------*/
2205 static int
2206 HSC_Scroll_Char_Backward(FORM *form)
2207 {
2208   T((T_CALLED("HSC_Scroll_Char_Backward(%p)"), (void *)form));
2209   returnCode(HSC_Generic(form, -1));
2210 }
2211
2212 /*---------------------------------------------------------------------------
2213 |   Facility      :  libnform
2214 |   Function      :  static int HSC_Horizontal_Line_Forward(FORM* form)
2215 |
2216 |   Description   :  Scroll single-line field forward a line
2217 |
2218 |   Return Values :  E_OK                - success
2219 |                    E_REQUEST_DENIED    - no data ahead
2220 +--------------------------------------------------------------------------*/
2221 static int
2222 HSC_Horizontal_Line_Forward(FORM *form)
2223 {
2224   T((T_CALLED("HSC_Horizontal_Line_Forward(%p)"), (void *)form));
2225   returnCode(HSC_Generic(form, form->current->cols));
2226 }
2227
2228 /*---------------------------------------------------------------------------
2229 |   Facility      :  libnform
2230 |   Function      :  static int HSC_Horizontal_Half_Line_Forward(FORM* form)
2231 |
2232 |   Description   :  Scroll single-line field forward half a line
2233 |
2234 |   Return Values :  E_OK               - success
2235 |                    E_REQUEST_DENIED   - no data ahead
2236 +--------------------------------------------------------------------------*/
2237 static int
2238 HSC_Horizontal_Half_Line_Forward(FORM *form)
2239 {
2240   T((T_CALLED("HSC_Horizontal_Half_Line_Forward(%p)"), (void *)form));
2241   returnCode(HSC_Generic(form, (form->current->cols + 1) / 2));
2242 }
2243
2244 /*---------------------------------------------------------------------------
2245 |   Facility      :  libnform
2246 |   Function      :  static int HSC_Horizontal_Line_Backward(FORM* form)
2247 |
2248 |   Description   :  Scroll single-line field backward a line
2249 |
2250 |   Return Values :  E_OK                - success
2251 |                    E_REQUEST_DENIED    - no data behind
2252 +--------------------------------------------------------------------------*/
2253 static int
2254 HSC_Horizontal_Line_Backward(FORM *form)
2255 {
2256   T((T_CALLED("HSC_Horizontal_Line_Backward(%p)"), (void *)form));
2257   returnCode(HSC_Generic(form, -(form->current->cols)));
2258 }
2259
2260 /*---------------------------------------------------------------------------
2261 |   Facility      :  libnform
2262 |   Function      :  static int HSC_Horizontal_Half_Line_Backward(FORM* form)
2263 |
2264 |   Description   :  Scroll single-line field backward half a line
2265 |
2266 |   Return Values :  E_OK                - success
2267 |                    E_REQUEST_DENIED    - no data behind
2268 +--------------------------------------------------------------------------*/
2269 static int
2270 HSC_Horizontal_Half_Line_Backward(FORM *form)
2271 {
2272   T((T_CALLED("HSC_Horizontal_Half_Line_Backward(%p)"), (void *)form));
2273   returnCode(HSC_Generic(form, -((form->current->cols + 1) / 2)));
2274 }
2275
2276 /*----------------------------------------------------------------------------
2277   End of Horizontal scrolling routines
2278   --------------------------------------------------------------------------*/
2279
2280 /*----------------------------------------------------------------------------
2281   Helper routines for Field Editing
2282   --------------------------------------------------------------------------*/
2283
2284 /*---------------------------------------------------------------------------
2285 |   Facility      :  libnform
2286 |   Function      :  static bool Is_There_Room_For_A_Line(FORM * form)
2287 |
2288 |   Description   :  Check whether or not there is enough room in the
2289 |                    buffer to enter a whole line.
2290 |
2291 |   Return Values :  TRUE   - there is enough space
2292 |                    FALSE  - there is not enough space
2293 +--------------------------------------------------------------------------*/
2294 NCURSES_INLINE static bool
2295 Is_There_Room_For_A_Line(FORM *form)
2296 {
2297   FIELD *field = form->current;
2298   FIELD_CELL *begin_of_last_line, *s;
2299
2300   Synchronize_Buffer(form);
2301   begin_of_last_line = Address_Of_Row_In_Buffer(field, (field->drows - 1));
2302   s = After_End_Of_Data(begin_of_last_line, field->dcols);
2303   return ((s == begin_of_last_line) ? TRUE : FALSE);
2304 }
2305
2306 /*---------------------------------------------------------------------------
2307 |   Facility      :  libnform
2308 |   Function      :  static bool Is_There_Room_For_A_Char_In_Line(FORM * form)
2309 |
2310 |   Description   :  Checks whether or not there is room for a new character
2311 |                    in the current line.
2312 |
2313 |   Return Values :  TRUE    - there is room
2314 |                    FALSE   - there is not enough room (line full)
2315 +--------------------------------------------------------------------------*/
2316 NCURSES_INLINE static bool
2317 Is_There_Room_For_A_Char_In_Line(FORM *form)
2318 {
2319   int last_char_in_line;
2320
2321   wmove(form->w, form->currow, form->current->dcols - 1);
2322   last_char_in_line = (int)(winch(form->w) & A_CHARTEXT);
2323   wmove(form->w, form->currow, form->curcol);
2324   return (((last_char_in_line == form->current->pad) ||
2325            is_blank(last_char_in_line)) ? TRUE : FALSE);
2326 }
2327
2328 #define There_Is_No_Room_For_A_Char_In_Line(f) \
2329   !Is_There_Room_For_A_Char_In_Line(f)
2330
2331 /*---------------------------------------------------------------------------
2332 |   Facility      :  libnform
2333 |   Function      :  static int Insert_String(
2334 |                                             FORM * form,
2335 |                                             int row,
2336 |                                             char *txt,
2337 |                                             int  len )
2338 |
2339 |   Description   :  Insert the 'len' characters beginning at pointer 'txt'
2340 |                    into the 'row' of the 'form'. The insertion occurs
2341 |                    on the beginning of the row, all other characters are
2342 |                    moved to the right. After the text a pad character will
2343 |                    be inserted to separate the text from the rest. If
2344 |                    necessary the insertion moves characters on the next
2345 |                    line to make place for the requested insertion string.
2346 |
2347 |   Return Values :  E_OK              - success
2348 |                    E_REQUEST_DENIED  -
2349 |                    E_SYSTEM_ERROR    - system error
2350 +--------------------------------------------------------------------------*/
2351 static int
2352 Insert_String(FORM *form, int row, FIELD_CELL *txt, int len)
2353 {
2354   FIELD *field = form->current;
2355   FIELD_CELL *bp = Address_Of_Row_In_Buffer(field, row);
2356   int datalen = (int)(After_End_Of_Data(bp, field->dcols) - bp);
2357   int freelen = field->dcols - datalen;
2358   int requiredlen = len + 1;
2359   FIELD_CELL *split;
2360   int result = E_REQUEST_DENIED;
2361
2362   if (freelen >= requiredlen)
2363     {
2364       wmove(form->w, row, 0);
2365       myINSNSTR(form->w, txt, len);
2366       wmove(form->w, row, len);
2367       myINSNSTR(form->w, &myBLANK, 1);
2368       return E_OK;
2369     }
2370   else
2371     {
2372       /* we have to move characters on the next line. If we are on the
2373          last line this may work, if the field is growable */
2374       if ((row == (field->drows - 1)) && Growable(field))
2375         {
2376           if (!Field_Grown(field, 1))
2377             return (E_SYSTEM_ERROR);
2378           /* !!!Side-Effect : might be changed due to growth!!! */
2379           bp = Address_Of_Row_In_Buffer(field, row);
2380         }
2381
2382       if (row < (field->drows - 1))
2383         {
2384           split =
2385             After_Last_Whitespace_Character(bp,
2386                                             (int)(Get_Start_Of_Data(bp
2387                                                                     + field->dcols
2388                                                                     - requiredlen,
2389                                                                     requiredlen)
2390                                                   - bp));
2391           /* split points now to the first character of the portion of the
2392              line that must be moved to the next line */
2393           datalen = (int)(split - bp);  /* + freelen has to stay on this line   */
2394           freelen = field->dcols - (datalen + freelen);         /* for the next line */
2395
2396           if ((result = Insert_String(form, row + 1, split, freelen)) == E_OK)
2397             {
2398               wmove(form->w, row, datalen);
2399               wclrtoeol(form->w);
2400               wmove(form->w, row, 0);
2401               myINSNSTR(form->w, txt, len);
2402               wmove(form->w, row, len);
2403               myINSNSTR(form->w, &myBLANK, 1);
2404               return E_OK;
2405             }
2406         }
2407       return (result);
2408     }
2409 }
2410
2411 /*---------------------------------------------------------------------------
2412 |   Facility      :  libnform
2413 |   Function      :  static int Wrapping_Not_Necessary_Or_Wrapping_Ok(
2414 |                                             FORM * form)
2415 |
2416 |   Description   :  If a character has been entered into a field, it may
2417 |                    be that wrapping has to occur. This routine checks
2418 |                    whether or not wrapping is required and if so, performs
2419 |                    the wrapping.
2420 |
2421 |   Return Values :  E_OK              - no wrapping required or wrapping
2422 |                                        was successful
2423 |                    E_REQUEST_DENIED  -
2424 |                    E_SYSTEM_ERROR    - some system error
2425 +--------------------------------------------------------------------------*/
2426 static int
2427 Wrapping_Not_Necessary_Or_Wrapping_Ok(FORM *form)
2428 {
2429   FIELD *field = form->current;
2430   int result = E_REQUEST_DENIED;
2431   bool Last_Row = ((field->drows - 1) == form->currow);
2432
2433   if ((field->opts & O_WRAP) && /* wrapping wanted     */
2434       (!Single_Line_Field(field)) &&    /* must be multi-line  */
2435       (There_Is_No_Room_For_A_Char_In_Line(form)) &&    /* line is full        */
2436       (!Last_Row || Growable(field)))   /* there are more lines */
2437     {
2438       FIELD_CELL *bp;
2439       FIELD_CELL *split;
2440       int chars_to_be_wrapped;
2441       int chars_to_remain_on_line;
2442
2443       if (Last_Row)
2444         {
2445           /* the above logic already ensures, that in this case the field
2446              is growable */
2447           if (!Field_Grown(field, 1))
2448             return E_SYSTEM_ERROR;
2449         }
2450       bp = Address_Of_Current_Row_In_Buffer(form);
2451       Window_To_Buffer(form, field);
2452       split = After_Last_Whitespace_Character(bp, field->dcols);
2453       /* split points to the first character of the sequence to be brought
2454          on the next line */
2455       chars_to_remain_on_line = (int)(split - bp);
2456       chars_to_be_wrapped = field->dcols - chars_to_remain_on_line;
2457       if (chars_to_remain_on_line > 0)
2458         {
2459           if ((result = Insert_String(form, form->currow + 1, split,
2460                                       chars_to_be_wrapped)) == E_OK)
2461             {
2462               wmove(form->w, form->currow, chars_to_remain_on_line);
2463               wclrtoeol(form->w);
2464               if (form->curcol >= chars_to_remain_on_line)
2465                 {
2466                   form->currow++;
2467                   form->curcol -= chars_to_remain_on_line;
2468                 }
2469               return E_OK;
2470             }
2471         }
2472       else
2473         return E_OK;
2474       if (result != E_OK)
2475         {
2476           DeleteChar(form);
2477           Window_To_Buffer(form, field);
2478           result = E_REQUEST_DENIED;
2479         }
2480     }
2481   else
2482     result = E_OK;              /* wrapping was not necessary */
2483   return (result);
2484 }
2485
2486 /*----------------------------------------------------------------------------
2487   Field Editing routines
2488   --------------------------------------------------------------------------*/
2489
2490 /*---------------------------------------------------------------------------
2491 |   Facility      :  libnform
2492 |   Function      :  static int Field_Editing(
2493 |                                    int (* const fct) (FORM *),
2494 |                                    FORM * form)
2495 |
2496 |   Description   :  Generic routine for field editing requests. The driver
2497 |                    routines are only called for editable fields, the
2498 |                    _WINDOW_MODIFIED flag is set if editing occurred.
2499 |                    This is somewhat special due to the overload semantics
2500 |                    of the NEW_LINE and DEL_PREV requests.
2501 |
2502 |   Return Values :  Error code from low level drivers.
2503 +--------------------------------------------------------------------------*/
2504 static int
2505 Field_Editing(int (*const fct) (FORM *), FORM *form)
2506 {
2507   int res = E_REQUEST_DENIED;
2508
2509   /* We have to deal here with the specific case of the overloaded
2510      behavior of New_Line and Delete_Previous requests.
2511      They may end up in navigational requests if we are on the first
2512      character in a field. But navigation is also allowed on non-
2513      editable fields.
2514    */
2515   if ((fct == FE_Delete_Previous) &&
2516       (form->opts & O_BS_OVERLOAD) &&
2517       First_Position_In_Current_Field(form))
2518     {
2519       res = Inter_Field_Navigation(FN_Previous_Field, form);
2520     }
2521   else
2522     {
2523       if (fct == FE_New_Line)
2524         {
2525           if ((form->opts & O_NL_OVERLOAD) &&
2526               First_Position_In_Current_Field(form))
2527             {
2528               res = Inter_Field_Navigation(FN_Next_Field, form);
2529             }
2530           else
2531             /* FE_New_Line deals itself with the _WINDOW_MODIFIED flag */
2532             res = fct(form);
2533         }
2534       else
2535         {
2536           /* From now on, everything must be editable */
2537           if (form->current->opts & O_EDIT)
2538             {
2539               res = fct(form);
2540               if (res == E_OK)
2541                 form->status |= _WINDOW_MODIFIED;
2542             }
2543         }
2544     }
2545   return res;
2546 }
2547
2548 /*---------------------------------------------------------------------------
2549 |   Facility      :  libnform
2550 |   Function      :  static int FE_New_Line(FORM * form)
2551 |
2552 |   Description   :  Perform a new line request. This is rather complex
2553 |                    compared to other routines in this code due to the
2554 |                    rather difficult to understand description in the
2555 |                    manuals.
2556 |
2557 |   Return Values :  E_OK               - success
2558 |                    E_REQUEST_DENIED   - new line not allowed
2559 |                    E_SYSTEM_ERROR     - system error
2560 +--------------------------------------------------------------------------*/
2561 static int
2562 FE_New_Line(FORM *form)
2563 {
2564   FIELD *field = form->current;
2565   FIELD_CELL *bp, *t;
2566   bool Last_Row = ((field->drows - 1) == form->currow);
2567
2568   T((T_CALLED("FE_New_Line(%p)"), (void *)form));
2569   if (form->status & _OVLMODE)
2570     {
2571       if (Last_Row &&
2572           (!(Growable(field) && !Single_Line_Field(field))))
2573         {
2574           if (!(form->opts & O_NL_OVERLOAD))
2575             returnCode(E_REQUEST_DENIED);
2576           wmove(form->w, form->currow, form->curcol);
2577           wclrtoeol(form->w);
2578           /* we have to set this here, although it is also
2579              handled in the generic routine. The reason is,
2580              that FN_Next_Field may fail, but the form is
2581              definitively changed */
2582           form->status |= _WINDOW_MODIFIED;
2583           returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2584         }
2585       else
2586         {
2587           if (Last_Row && !Field_Grown(field, 1))
2588             {
2589               /* N.B.: due to the logic in the 'if', LastRow==TRUE
2590                  means here that the field is growable and not
2591                  a single-line field */
2592               returnCode(E_SYSTEM_ERROR);
2593             }
2594           wmove(form->w, form->currow, form->curcol);
2595           wclrtoeol(form->w);
2596           form->currow++;
2597           form->curcol = 0;
2598           form->status |= _WINDOW_MODIFIED;
2599           returnCode(E_OK);
2600         }
2601     }
2602   else
2603     {
2604       /* Insert Mode */
2605       if (Last_Row &&
2606           !(Growable(field) && !Single_Line_Field(field)))
2607         {
2608           if (!(form->opts & O_NL_OVERLOAD))
2609             returnCode(E_REQUEST_DENIED);
2610           returnCode(Inter_Field_Navigation(FN_Next_Field, form));
2611         }
2612       else
2613         {
2614           bool May_Do_It = !Last_Row && Is_There_Room_For_A_Line(form);
2615
2616           if (!(May_Do_It || Growable(field)))
2617             returnCode(E_REQUEST_DENIED);
2618           if (!May_Do_It && !Field_Grown(field, 1))
2619             returnCode(E_SYSTEM_ERROR);
2620
2621           bp = Address_Of_Current_Position_In_Buffer(form);
2622           t = After_End_Of_Data(bp, field->dcols - form->curcol);
2623           wmove(form->w, form->currow, form->curcol);
2624           wclrtoeol(form->w);
2625           form->currow++;
2626           form->curcol = 0;
2627           wmove(form->w, form->currow, form->curcol);
2628           winsertln(form->w);
2629           myADDNSTR(form->w, bp, (int)(t - bp));
2630           form->status |= _WINDOW_MODIFIED;
2631           returnCode(E_OK);
2632         }
2633     }
2634 }
2635
2636 /*---------------------------------------------------------------------------
2637 |   Facility      :  libnform
2638 |   Function      :  static int FE_Insert_Character(FORM * form)
2639 |
2640 |   Description   :  Insert blank character at the cursor position
2641 |
2642 |   Return Values :  E_OK
2643 |                    E_REQUEST_DENIED
2644 +--------------------------------------------------------------------------*/
2645 static int
2646 FE_Insert_Character(FORM *form)
2647 {
2648   FIELD *field = form->current;
2649   int result = E_REQUEST_DENIED;
2650
2651   T((T_CALLED("FE_Insert_Character(%p)"), (void *)form));
2652   if (Check_Char(form, field, field->type, (int)C_BLANK,
2653                  (TypeArgument *)(field->arg)))
2654     {
2655       bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
2656
2657       if (There_Is_Room ||
2658           ((Single_Line_Field(field) && Growable(field))))
2659         {
2660           if (!There_Is_Room && !Field_Grown(field, 1))
2661             result = E_SYSTEM_ERROR;
2662           else
2663             {
2664               winsch(form->w, (chtype)C_BLANK);
2665               result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form);
2666             }
2667         }
2668     }
2669   returnCode(result);
2670 }
2671
2672 /*---------------------------------------------------------------------------
2673 |   Facility      :  libnform
2674 |   Function      :  static int FE_Insert_Line(FORM * form)
2675 |
2676 |   Description   :  Insert a blank line at the cursor position
2677 |
2678 |   Return Values :  E_OK               - success
2679 |                    E_REQUEST_DENIED   - line can not be inserted
2680 +--------------------------------------------------------------------------*/
2681 static int
2682 FE_Insert_Line(FORM *form)
2683 {
2684   FIELD *field = form->current;
2685   int result = E_REQUEST_DENIED;
2686
2687   T((T_CALLED("FE_Insert_Line(%p)"), (void *)form));
2688   if (Check_Char(form, field,
2689                  field->type, (int)C_BLANK, (TypeArgument *)(field->arg)))
2690     {
2691       bool Maybe_Done = (form->currow != (field->drows - 1)) &&
2692       Is_There_Room_For_A_Line(form);
2693
2694       if (!Single_Line_Field(field) &&
2695           (Maybe_Done || Growable(field)))
2696         {
2697           if (!Maybe_Done && !Field_Grown(field, 1))
2698             result = E_SYSTEM_ERROR;
2699           else
2700             {
2701               form->curcol = 0;
2702               winsertln(form->w);
2703               result = E_OK;
2704             }
2705         }
2706     }
2707   returnCode(result);
2708 }
2709
2710 /*---------------------------------------------------------------------------
2711 |   Facility      :  libnform
2712 |   Function      :  static int FE_Delete_Character(FORM * form)
2713 |
2714 |   Description   :  Delete character at the cursor position
2715 |
2716 |   Return Values :  E_OK    - success
2717 +--------------------------------------------------------------------------*/
2718 static int
2719 FE_Delete_Character(FORM *form)
2720 {
2721   T((T_CALLED("FE_Delete_Character(%p)"), (void *)form));
2722   DeleteChar(form);
2723   returnCode(E_OK);
2724 }
2725
2726 /*---------------------------------------------------------------------------
2727 |   Facility      :  libnform
2728 |   Function      :  static int FE_Delete_Previous(FORM * form)
2729 |
2730 |   Description   :  Delete character before cursor. Again this is a rather
2731 |                    difficult piece compared to others due to the overloading
2732 |                    semantics of backspace.
2733 |                    N.B.: The case of overloaded BS on first field position
2734 |                          is already handled in the generic routine.
2735 |
2736 |   Return Values :  E_OK                - success
2737 |                    E_REQUEST_DENIED    - Character can't be deleted
2738 +--------------------------------------------------------------------------*/
2739 static int
2740 FE_Delete_Previous(FORM *form)
2741 {
2742   FIELD *field = form->current;
2743
2744   T((T_CALLED("FE_Delete_Previous(%p)"), (void *)form));
2745   if (First_Position_In_Current_Field(form))
2746     returnCode(E_REQUEST_DENIED);
2747
2748   if ((--(form->curcol)) < 0)
2749     {
2750       FIELD_CELL *this_line, *prev_line, *prev_end, *this_end;
2751       int this_row = form->currow;
2752
2753       form->curcol++;
2754       if (form->status & _OVLMODE)
2755         returnCode(E_REQUEST_DENIED);
2756
2757       prev_line = Address_Of_Row_In_Buffer(field, (form->currow - 1));
2758       this_line = Address_Of_Row_In_Buffer(field, (form->currow));
2759       Synchronize_Buffer(form);
2760       prev_end = After_End_Of_Data(prev_line, field->dcols);
2761       this_end = After_End_Of_Data(this_line, field->dcols);
2762       if ((int)(this_end - this_line) >
2763           (field->cols - (int)(prev_end - prev_line)))
2764         returnCode(E_REQUEST_DENIED);
2765       wmove(form->w, form->currow, form->curcol);
2766       wdeleteln(form->w);
2767       Adjust_Cursor_Position(form, prev_end);
2768       /*
2769        * If we did not really move to the previous line, help the user a
2770        * little.  It is however a little inconsistent.  Normally, when
2771        * backspacing around the point where text wraps to a new line in a
2772        * multi-line form, we absorb one keystroke for the wrapping point.  That
2773        * is consistent with SVr4 forms.  However, SVr4 does not allow typing
2774        * into the last column of the field, and requires the user to enter a
2775        * newline to move to the next line.  Therefore it can consistently eat
2776        * that keystroke.  Since ncurses allows the last column, it wraps
2777        * automatically (given the proper options).  But we cannot eat the
2778        * keystroke to back over the wrapping point, since that would put the
2779        * cursor past the end of the form field.  In this case, just delete the
2780        * character at the end of the field.
2781        */
2782       if (form->currow == this_row && this_row > 0)
2783         {
2784           form->currow -= 1;
2785           form->curcol = field->dcols - 1;
2786           DeleteChar(form);
2787         }
2788       else
2789         {
2790           wmove(form->w, form->currow, form->curcol);
2791           myADDNSTR(form->w, this_line, (int)(this_end - this_line));
2792         }
2793     }
2794   else
2795     {
2796       DeleteChar(form);
2797     }
2798   returnCode(E_OK);
2799 }
2800
2801 /*---------------------------------------------------------------------------
2802 |   Facility      :  libnform
2803 |   Function      :  static int FE_Delete_Line(FORM * form)
2804 |
2805 |   Description   :  Delete line at cursor position.
2806 |
2807 |   Return Values :  E_OK  - success
2808 +--------------------------------------------------------------------------*/
2809 static int
2810 FE_Delete_Line(FORM *form)
2811 {
2812   T((T_CALLED("FE_Delete_Line(%p)"), (void *)form));
2813   form->curcol = 0;
2814   wdeleteln(form->w);
2815   returnCode(E_OK);
2816 }
2817
2818 /*---------------------------------------------------------------------------
2819 |   Facility      :  libnform
2820 |   Function      :  static int FE_Delete_Word(FORM * form)
2821 |
2822 |   Description   :  Delete word at cursor position
2823 |
2824 |   Return Values :  E_OK               - success
2825 |                    E_REQUEST_DENIED   - failure
2826 +--------------------------------------------------------------------------*/
2827 static int
2828 FE_Delete_Word(FORM *form)
2829 {
2830   FIELD *field = form->current;
2831   FIELD_CELL *bp = Address_Of_Current_Row_In_Buffer(form);
2832   FIELD_CELL *ep = bp + field->dcols;
2833   FIELD_CELL *cp = bp + form->curcol;
2834   FIELD_CELL *s;
2835
2836   T((T_CALLED("FE_Delete_Word(%p)"), (void *)form));
2837   Synchronize_Buffer(form);
2838   if (ISBLANK(*cp))
2839     returnCode(E_REQUEST_DENIED);       /* not in word */
2840
2841   /* move cursor to begin of word and erase to end of screen-line */
2842   Adjust_Cursor_Position(form,
2843                          After_Last_Whitespace_Character(bp, form->curcol));
2844   wmove(form->w, form->currow, form->curcol);
2845   wclrtoeol(form->w);
2846
2847   /* skip over word in buffer */
2848   s = Get_First_Whitespace_Character(cp, (int)(ep - cp));
2849   /* to begin of next word    */
2850   s = Get_Start_Of_Data(s, (int)(ep - s));
2851   if ((s != cp) && !ISBLANK(*s))
2852     {
2853       /* copy remaining line to window */
2854       myADDNSTR(form->w, s, (int)(s - After_End_Of_Data(s, (int)(ep - s))));
2855     }
2856   returnCode(E_OK);
2857 }
2858
2859 /*---------------------------------------------------------------------------
2860 |   Facility      :  libnform
2861 |   Function      :  static int FE_Clear_To_End_Of_Line(FORM * form)
2862 |
2863 |   Description   :  Clear to end of current line.
2864 |
2865 |   Return Values :  E_OK   - success
2866 +--------------------------------------------------------------------------*/
2867 static int
2868 FE_Clear_To_End_Of_Line(FORM *form)
2869 {
2870   T((T_CALLED("FE_Clear_To_End_Of_Line(%p)"), (void *)form));
2871   wmove(form->w, form->currow, form->curcol);
2872   wclrtoeol(form->w);
2873   returnCode(E_OK);
2874 }
2875
2876 /*---------------------------------------------------------------------------
2877 |   Facility      :  libnform
2878 |   Function      :  static int FE_Clear_To_End_Of_Field(FORM * form)
2879 |
2880 |   Description   :  Clear to end of field.
2881 |
2882 |   Return Values :  E_OK   - success
2883 +--------------------------------------------------------------------------*/
2884 static int
2885 FE_Clear_To_End_Of_Field(FORM *form)
2886 {
2887   T((T_CALLED("FE_Clear_To_End_Of_Field(%p)"), (void *)form));
2888   wmove(form->w, form->currow, form->curcol);
2889   wclrtobot(form->w);
2890   returnCode(E_OK);
2891 }
2892
2893 /*---------------------------------------------------------------------------
2894 |   Facility      :  libnform
2895 |   Function      :  static int FE_Clear_Field(FORM * form)
2896 |
2897 |   Description   :  Clear entire field.
2898 |
2899 |   Return Values :  E_OK   - success
2900 +--------------------------------------------------------------------------*/
2901 static int
2902 FE_Clear_Field(FORM *form)
2903 {
2904   T((T_CALLED("FE_Clear_Field(%p)"), (void *)form));
2905   form->currow = form->curcol = 0;
2906   werase(form->w);
2907   returnCode(E_OK);
2908 }
2909 /*----------------------------------------------------------------------------
2910   END of Field Editing routines
2911   --------------------------------------------------------------------------*/
2912
2913 /*----------------------------------------------------------------------------
2914   Edit Mode routines
2915   --------------------------------------------------------------------------*/
2916
2917 /*---------------------------------------------------------------------------
2918 |   Facility      :  libnform
2919 |   Function      :  static int EM_Overlay_Mode(FORM * form)
2920 |
2921 |   Description   :  Switch to overlay mode.
2922 |
2923 |   Return Values :  E_OK   - success
2924 +--------------------------------------------------------------------------*/
2925 static int
2926 EM_Overlay_Mode(FORM *form)
2927 {
2928   T((T_CALLED("EM_Overlay_Mode(%p)"), (void *)form));
2929   form->status |= _OVLMODE;
2930   returnCode(E_OK);
2931 }
2932
2933 /*---------------------------------------------------------------------------
2934 |   Facility      :  libnform
2935 |   Function      :  static int EM_Insert_Mode(FORM * form)
2936 |
2937 |   Description   :  Switch to insert mode
2938 |
2939 |   Return Values :  E_OK   - success
2940 +--------------------------------------------------------------------------*/
2941 static int
2942 EM_Insert_Mode(FORM *form)
2943 {
2944   T((T_CALLED("EM_Insert_Mode(%p)"), (void *)form));
2945   form->status &= ~_OVLMODE;
2946   returnCode(E_OK);
2947 }
2948
2949 /*----------------------------------------------------------------------------
2950   END of Edit Mode routines
2951   --------------------------------------------------------------------------*/
2952
2953 /*----------------------------------------------------------------------------
2954   Helper routines for Choice Requests
2955   --------------------------------------------------------------------------*/
2956
2957 /*---------------------------------------------------------------------------
2958 |   Facility      :  libnform
2959 |   Function      :  static bool Next_Choice(FORM * form,
2960 |                                            FIELDTYPE * typ,
2961 |                                            FIELD * field,
2962 |                                            TypeArgument *argp)
2963 |
2964 |   Description   :  Get the next field choice. For linked types this is
2965 |                    done recursively.
2966 |
2967 |   Return Values :  TRUE    - next choice successfully retrieved
2968 |                    FALSE   - couldn't retrieve next choice
2969 +--------------------------------------------------------------------------*/
2970 static bool
2971 Next_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
2972 {
2973   if (!typ || !(typ->status & _HAS_CHOICE))
2974     return FALSE;
2975
2976   if (typ->status & _LINKED_TYPE)
2977     {
2978       assert(argp);
2979       return (
2980                Next_Choice(form, typ->left, field, argp->left) ||
2981                Next_Choice(form, typ->right, field, argp->right));
2982     }
2983   else
2984     {
2985 #if NCURSES_INTEROP_FUNCS
2986       assert(typ->enum_next.onext);
2987       if (typ->status & _GENERIC)
2988         return typ->enum_next.gnext(form, field, (void *)argp);
2989       else
2990         return typ->enum_next.onext(field, (void *)argp);
2991 #else
2992       assert(typ->next);
2993       return typ->next(field, (void *)argp);
2994 #endif
2995     }
2996 }
2997
2998 /*---------------------------------------------------------------------------
2999 |   Facility      :  libnform
3000 |   Function      :  static bool Previous_Choice(FORM * form,
3001 |                                                FIELDTYPE * typ,
3002 |                                                FIELD * field,
3003 |                                                TypeArgument *argp)
3004 |
3005 |   Description   :  Get the previous field choice. For linked types this
3006 |                    is done recursively.
3007 |
3008 |   Return Values :  TRUE    - previous choice successfully retrieved
3009 |                    FALSE   - couldn't retrieve previous choice
3010 +--------------------------------------------------------------------------*/
3011 static bool
3012 Previous_Choice(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3013 {
3014   if (!typ || !(typ->status & _HAS_CHOICE))
3015     return FALSE;
3016
3017   if (typ->status & _LINKED_TYPE)
3018     {
3019       assert(argp);
3020       return (
3021                Previous_Choice(form, typ->left, field, argp->left) ||
3022                Previous_Choice(form, typ->right, field, argp->right));
3023     }
3024   else
3025     {
3026 #if NCURSES_INTEROP_FUNCS
3027       assert(typ->enum_prev.oprev);
3028       if (typ->status & _GENERIC)
3029         return typ->enum_prev.gprev(form, field, (void *)argp);
3030       else
3031         return typ->enum_prev.oprev(field, (void *)argp);
3032 #else
3033       assert(typ->prev);
3034       return typ->prev(field, (void *)argp);
3035 #endif
3036     }
3037 }
3038 /*----------------------------------------------------------------------------
3039   End of Helper routines for Choice Requests
3040   --------------------------------------------------------------------------*/
3041
3042 /*----------------------------------------------------------------------------
3043   Routines for Choice Requests
3044   --------------------------------------------------------------------------*/
3045
3046 /*---------------------------------------------------------------------------
3047 |   Facility      :  libnform
3048 |   Function      :  static int CR_Next_Choice(FORM * form)
3049 |
3050 |   Description   :  Get the next field choice.
3051 |
3052 |   Return Values :  E_OK              - success
3053 |                    E_REQUEST_DENIED  - next choice couldn't be retrieved
3054 +--------------------------------------------------------------------------*/
3055 static int
3056 CR_Next_Choice(FORM *form)
3057 {
3058   FIELD *field = form->current;
3059
3060   T((T_CALLED("CR_Next_Choice(%p)"), (void *)form));
3061   Synchronize_Buffer(form);
3062   returnCode((Next_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3063              ? E_OK
3064              : E_REQUEST_DENIED);
3065 }
3066
3067 /*---------------------------------------------------------------------------
3068 |   Facility      :  libnform
3069 |   Function      :  static int CR_Previous_Choice(FORM * form)
3070 |
3071 |   Description   :  Get the previous field choice.
3072 |
3073 |   Return Values :  E_OK              - success
3074 |                    E_REQUEST_DENIED  - prev. choice couldn't be retrieved
3075 +--------------------------------------------------------------------------*/
3076 static int
3077 CR_Previous_Choice(FORM *form)
3078 {
3079   FIELD *field = form->current;
3080
3081   T((T_CALLED("CR_Previous_Choice(%p)"), (void *)form));
3082   Synchronize_Buffer(form);
3083   returnCode((Previous_Choice(form, field->type, field, (TypeArgument *)(field->arg)))
3084              ? E_OK
3085              : E_REQUEST_DENIED);
3086 }
3087 /*----------------------------------------------------------------------------
3088   End of Routines for Choice Requests
3089   --------------------------------------------------------------------------*/
3090
3091 /*----------------------------------------------------------------------------
3092   Helper routines for Field Validations.
3093   --------------------------------------------------------------------------*/
3094
3095 /*---------------------------------------------------------------------------
3096 |   Facility      :  libnform
3097 |   Function      :  static bool Check_Field(FORM* form,
3098 |                                            FIELDTYPE * typ,
3099 |                                            FIELD * field,
3100 |                                            TypeArgument * argp)
3101 |
3102 |   Description   :  Check the field according to its fieldtype and its
3103 |                    actual arguments. For linked fieldtypes this is done
3104 |                    recursively.
3105 |
3106 |   Return Values :  TRUE       - field is valid
3107 |                    FALSE      - field is invalid.
3108 +--------------------------------------------------------------------------*/
3109 static bool
3110 Check_Field(FORM *form, FIELDTYPE *typ, FIELD *field, TypeArgument *argp)
3111 {
3112   if (typ)
3113     {
3114       if (field->opts & O_NULLOK)
3115         {
3116           FIELD_CELL *bp = field->buf;
3117
3118           assert(bp);
3119           while (ISBLANK(*bp))
3120             {
3121               bp++;
3122             }
3123           if (CharOf(*bp) == 0)
3124             return TRUE;
3125         }
3126
3127       if (typ->status & _LINKED_TYPE)
3128         {
3129           assert(argp);
3130           return (
3131                    Check_Field(form, typ->left, field, argp->left) ||
3132                    Check_Field(form, typ->right, field, argp->right));
3133         }
3134       else
3135         {
3136 #if NCURSES_INTEROP_FUNCS
3137           if (typ->fieldcheck.ofcheck)
3138             {
3139               if (typ->status & _GENERIC)
3140                 return typ->fieldcheck.gfcheck(form, field, (void *)argp);
3141               else
3142                 return typ->fieldcheck.ofcheck(field, (void *)argp);
3143             }
3144 #else
3145           if (typ->fcheck)
3146             return typ->fcheck(field, (void *)argp);
3147 #endif
3148         }
3149     }
3150   return TRUE;
3151 }
3152
3153 /*---------------------------------------------------------------------------
3154 |   Facility      :  libnform
3155 |   Function      :  bool _nc_Internal_Validation(FORM * form )
3156 |
3157 |   Description   :  Validate the current field of the form.
3158 |
3159 |   Return Values :  TRUE  - field is valid
3160 |                    FALSE - field is invalid
3161 +--------------------------------------------------------------------------*/
3162 NCURSES_EXPORT(bool)
3163 _nc_Internal_Validation(FORM *form)
3164 {
3165   FIELD *field;
3166
3167   field = form->current;
3168
3169   Synchronize_Buffer(form);
3170   if ((form->status & _FCHECK_REQUIRED) ||
3171       (!(field->opts & O_PASSOK)))
3172     {
3173       if (!Check_Field(form, field->type, field, (TypeArgument *)(field->arg)))
3174         return FALSE;
3175       form->status &= ~_FCHECK_REQUIRED;
3176       field->status |= _CHANGED;
3177       Synchronize_Linked_Fields(field);
3178     }
3179   return TRUE;
3180 }
3181 /*----------------------------------------------------------------------------
3182   End of Helper routines for Field Validations.
3183   --------------------------------------------------------------------------*/
3184
3185 /*----------------------------------------------------------------------------
3186   Routines for Field Validation.
3187   --------------------------------------------------------------------------*/
3188
3189 /*---------------------------------------------------------------------------
3190 |   Facility      :  libnform
3191 |   Function      :  static int FV_Validation(FORM * form)
3192 |
3193 |   Description   :  Validate the current field of the form.
3194 |
3195 |   Return Values :  E_OK             - field valid
3196 |                    E_INVALID_FIELD  - field not valid
3197 +--------------------------------------------------------------------------*/
3198 static int
3199 FV_Validation(FORM *form)
3200 {
3201   T((T_CALLED("FV_Validation(%p)"), (void *)form));
3202   if (_nc_Internal_Validation(form))
3203     returnCode(E_OK);
3204   else
3205     returnCode(E_INVALID_FIELD);
3206 }
3207 /*----------------------------------------------------------------------------
3208   End of routines for Field Validation.
3209   --------------------------------------------------------------------------*/
3210
3211 /*----------------------------------------------------------------------------
3212   Helper routines for Inter-Field Navigation
3213   --------------------------------------------------------------------------*/
3214
3215 /*---------------------------------------------------------------------------
3216 |   Facility      :  libnform
3217 |   Function      :  static FIELD *Next_Field_On_Page(FIELD * field)
3218 |
3219 |   Description   :  Get the next field after the given field on the current
3220 |                    page. The order of fields is the one defined by the
3221 |                    fields array. Only visible and active fields are
3222 |                    counted.
3223 |
3224 |   Return Values :  Pointer to the next field.
3225 +--------------------------------------------------------------------------*/
3226 NCURSES_INLINE static FIELD *
3227 Next_Field_On_Page(FIELD *field)
3228 {
3229   FORM *form = field->form;
3230   FIELD **field_on_page = &form->field[field->index];
3231   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3232   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3233
3234   do
3235     {
3236       field_on_page =
3237         (field_on_page == last_on_page) ? first_on_page : field_on_page + 1;
3238       if (Field_Is_Selectable(*field_on_page))
3239         break;
3240     }
3241   while (field != (*field_on_page));
3242   return (*field_on_page);
3243 }
3244
3245 /*---------------------------------------------------------------------------
3246 |   Facility      :  libnform
3247 |   Function      :  FIELD* _nc_First_Active_Field(FORM * form)
3248 |
3249 |   Description   :  Get the first active field on the current page,
3250 |                    if there are such. If there are none, get the first
3251 |                    visible field on the page. If there are also none,
3252 |                    we return the first field on page and hope the best.
3253 |
3254 |   Return Values :  Pointer to calculated field.
3255 +--------------------------------------------------------------------------*/
3256 NCURSES_EXPORT(FIELD *)
3257 _nc_First_Active_Field(FORM *form)
3258 {
3259   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3260   FIELD *proposed = Next_Field_On_Page(*last_on_page);
3261
3262   if (proposed == *last_on_page)
3263     {
3264       /* there might be the special situation, where there is no
3265          active and visible field on the current page. We then select
3266          the first visible field on this readonly page
3267        */
3268       if (Field_Is_Not_Selectable(proposed))
3269         {
3270           FIELD **field = &form->field[proposed->index];
3271           FIELD **first = &form->field[form->page[form->curpage].pmin];
3272
3273           do
3274             {
3275               field = (field == last_on_page) ? first : field + 1;
3276               if (((*field)->opts & O_VISIBLE))
3277                 break;
3278             }
3279           while (proposed != (*field));
3280
3281           proposed = *field;
3282
3283           if ((proposed == *last_on_page) && !(proposed->opts & O_VISIBLE))
3284             {
3285               /* This means, there is also no visible field on the page.
3286                  So we propose the first one and hope the very best...
3287                  Some very clever user has designed a readonly and invisible
3288                  page on this form.
3289                */
3290               proposed = *first;
3291             }
3292         }
3293     }
3294   return (proposed);
3295 }
3296
3297 /*---------------------------------------------------------------------------
3298 |   Facility      :  libnform
3299 |   Function      :  static FIELD *Previous_Field_On_Page(FIELD * field)
3300 |
3301 |   Description   :  Get the previous field before the given field on the
3302 |                    current page. The order of fields is the one defined by
3303 |                    the fields array. Only visible and active fields are
3304 |                    counted.
3305 |
3306 |   Return Values :  Pointer to the previous field.
3307 +--------------------------------------------------------------------------*/
3308 NCURSES_INLINE static FIELD *
3309 Previous_Field_On_Page(FIELD *field)
3310 {
3311   FORM *form = field->form;
3312   FIELD **field_on_page = &form->field[field->index];
3313   FIELD **first_on_page = &form->field[form->page[form->curpage].pmin];
3314   FIELD **last_on_page = &form->field[form->page[form->curpage].pmax];
3315
3316   do
3317     {
3318       field_on_page =
3319         (field_on_page == first_on_page) ? last_on_page : field_on_page - 1;
3320       if (Field_Is_Selectable(*field_on_page))
3321         break;
3322     }
3323   while (field != (*field_on_page));
3324
3325   return (*field_on_page);
3326 }
3327
3328 /*---------------------------------------------------------------------------
3329 |   Facility      :  libnform
3330 |   Function      :  static FIELD *Sorted_Next_Field(FIELD * field)
3331 |
3332 |   Description   :  Get the next field after the given field on the current
3333 |                    page. The order of fields is the one defined by the
3334 |                    (row,column) geometry, rows are major.
3335 |
3336 |   Return Values :  Pointer to the next field.
3337 +--------------------------------------------------------------------------*/
3338 NCURSES_INLINE static FIELD *
3339 Sorted_Next_Field(FIELD *field)
3340 {
3341   FIELD *field_on_page = field;
3342
3343   do
3344     {
3345       field_on_page = field_on_page->snext;
3346       if (Field_Is_Selectable(field_on_page))
3347         break;
3348     }
3349   while (field_on_page != field);
3350
3351   return (field_on_page);
3352 }
3353
3354 /*---------------------------------------------------------------------------
3355 |   Facility      :  libnform
3356 |   Function      :  static FIELD *Sorted_Previous_Field(FIELD * field)
3357 |
3358 |   Description   :  Get the previous field before the given field on the
3359 |                    current page. The order of fields is the one defined
3360 |                    by the (row,column) geometry, rows are major.
3361 |
3362 |   Return Values :  Pointer to the previous field.
3363 +--------------------------------------------------------------------------*/
3364 NCURSES_INLINE static FIELD *
3365 Sorted_Previous_Field(FIELD *field)
3366 {
3367   FIELD *field_on_page = field;
3368
3369   do
3370     {
3371       field_on_page = field_on_page->sprev;
3372       if (Field_Is_Selectable(field_on_page))
3373         break;
3374     }
3375   while (field_on_page != field);
3376
3377   return (field_on_page);
3378 }
3379
3380 /*---------------------------------------------------------------------------
3381 |   Facility      :  libnform
3382 |   Function      :  static FIELD *Left_Neighbor_Field(FIELD * field)
3383 |
3384 |   Description   :  Get the left neighbor of the field on the same line
3385 |                    and the same page. Cycles through the line.
3386 |
3387 |   Return Values :  Pointer to left neighbor field.
3388 +--------------------------------------------------------------------------*/
3389 NCURSES_INLINE static FIELD *
3390 Left_Neighbor_Field(FIELD *field)
3391 {
3392   FIELD *field_on_page = field;
3393
3394   /* For a field that has really a left neighbor, the while clause
3395      immediately fails and the loop is left, positioned at the right
3396      neighbor. Otherwise we cycle backwards through the sorted field list
3397      until we enter the same line (from the right end).
3398    */
3399   do
3400     {
3401       field_on_page = Sorted_Previous_Field(field_on_page);
3402     }
3403   while (field_on_page->frow != field->frow);
3404
3405   return (field_on_page);
3406 }
3407
3408 /*---------------------------------------------------------------------------
3409 |   Facility      :  libnform
3410 |   Function      :  static FIELD *Right_Neighbor_Field(FIELD * field)
3411 |
3412 |   Description   :  Get the right neighbor of the field on the same line
3413 |                    and the same page.
3414 |
3415 |   Return Values :  Pointer to right neighbor field.
3416 +--------------------------------------------------------------------------*/
3417 NCURSES_INLINE static FIELD *
3418 Right_Neighbor_Field(FIELD *field)
3419 {
3420   FIELD *field_on_page = field;
3421
3422   /* See the comments on Left_Neighbor_Field to understand how it works */
3423   do
3424     {
3425       field_on_page = Sorted_Next_Field(field_on_page);
3426     }
3427   while (field_on_page->frow != field->frow);
3428
3429   return (field_on_page);
3430 }
3431
3432 /*---------------------------------------------------------------------------
3433 |   Facility      :  libnform
3434 |   Function      :  static FIELD *Upper_Neighbor_Field(FIELD * field)
3435 |
3436 |   Description   :  Because of the row-major nature of sorting the fields,
3437 |                    it is more difficult to define whats the upper neighbor
3438 |                    field really means. We define that it must be on a
3439 |                    'previous' line (cyclic order!) and is the rightmost
3440 |                    field laying on the left side of the given field. If
3441 |                    this set is empty, we take the first field on the line.
3442 |
3443 |   Return Values :  Pointer to the upper neighbor field.
3444 +--------------------------------------------------------------------------*/
3445 static FIELD *
3446 Upper_Neighbor_Field(FIELD *field)
3447 {
3448   FIELD *field_on_page = field;
3449   int frow = field->frow;
3450   int fcol = field->fcol;
3451
3452   /* Walk back to the 'previous' line. The second term in the while clause
3453      just guarantees that we stop if we cycled through the line because
3454      there might be no 'previous' line if the page has just one line.
3455    */
3456   do
3457     {
3458       field_on_page = Sorted_Previous_Field(field_on_page);
3459     }
3460   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3461
3462   if (field_on_page->frow != frow)
3463     {
3464       /* We really found a 'previous' line. We are positioned at the
3465          rightmost field on this line */
3466       frow = field_on_page->frow;
3467
3468       /* We walk to the left as long as we are really right of the
3469          field. */
3470       while (field_on_page->frow == frow && field_on_page->fcol > fcol)
3471         field_on_page = Sorted_Previous_Field(field_on_page);
3472
3473       /* If we wrapped, just go to the right which is the first field on
3474          the row */
3475       if (field_on_page->frow != frow)
3476         field_on_page = Sorted_Next_Field(field_on_page);
3477     }
3478
3479   return (field_on_page);
3480 }
3481
3482 /*---------------------------------------------------------------------------
3483 |   Facility      :  libnform
3484 |   Function      :  static FIELD *Down_Neighbor_Field(FIELD * field)
3485 |
3486 |   Description   :  Because of the row-major nature of sorting the fields,
3487 |                    its more difficult to define whats the down neighbor
3488 |                    field really means. We define that it must be on a
3489 |                    'next' line (cyclic order!) and is the leftmost
3490 |                    field laying on the right side of the given field. If
3491 |                    this set is empty, we take the last field on the line.
3492 |
3493 |   Return Values :  Pointer to the upper neighbor field.
3494 +--------------------------------------------------------------------------*/
3495 static FIELD *
3496 Down_Neighbor_Field(FIELD *field)
3497 {
3498   FIELD *field_on_page = field;
3499   int frow = field->frow;
3500   int fcol = field->fcol;
3501
3502   /* Walk forward to the 'next' line. The second term in the while clause
3503      just guarantees that we stop if we cycled through the line because
3504      there might be no 'next' line if the page has just one line.
3505    */
3506   do
3507     {
3508       field_on_page = Sorted_Next_Field(field_on_page);
3509     }
3510   while (field_on_page->frow == frow && field_on_page->fcol != fcol);
3511
3512   if (field_on_page->frow != frow)
3513     {
3514       /* We really found a 'next' line. We are positioned at the rightmost
3515          field on this line */
3516       frow = field_on_page->frow;
3517
3518       /* We walk to the right as long as we are really left of the
3519          field. */
3520       while (field_on_page->frow == frow && field_on_page->fcol < fcol)
3521         field_on_page = Sorted_Next_Field(field_on_page);
3522
3523       /* If we wrapped, just go to the left which is the last field on
3524          the row */
3525       if (field_on_page->frow != frow)
3526         field_on_page = Sorted_Previous_Field(field_on_page);
3527     }
3528
3529   return (field_on_page);
3530 }
3531
3532 /*----------------------------------------------------------------------------
3533   Inter-Field Navigation routines
3534   --------------------------------------------------------------------------*/
3535
3536 /*---------------------------------------------------------------------------
3537 |   Facility      :  libnform
3538 |   Function      :  static int Inter_Field_Navigation(
3539 |                                           int (* const fct) (FORM *),
3540 |                                           FORM * form)
3541 |
3542 |   Description   :  Generic behavior for changing the current field, the
3543 |                    field is left and a new field is entered. So the field
3544 |                    must be validated and the field init/term hooks must
3545 |                    be called.
3546 |
3547 |   Return Values :  E_OK                - success
3548 |                    E_INVALID_FIELD     - field is invalid
3549 |                    some other          - error from subordinate call
3550 +--------------------------------------------------------------------------*/
3551 static int
3552 Inter_Field_Navigation(int (*const fct) (FORM *), FORM *form)
3553 {
3554   int res;
3555
3556   if (!_nc_Internal_Validation(form))
3557     res = E_INVALID_FIELD;
3558   else
3559     {
3560       Call_Hook(form, fieldterm);
3561       res = fct(form);
3562       Call_Hook(form, fieldinit);
3563     }
3564   return res;
3565 }
3566
3567 /*---------------------------------------------------------------------------
3568 |   Facility      :  libnform
3569 |   Function      :  static int FN_Next_Field(FORM * form)
3570 |
3571 |   Description   :  Move to the next field on the current page of the form
3572 |
3573 |   Return Values :  E_OK                 - success
3574 |                    != E_OK              - error from subordinate call
3575 +--------------------------------------------------------------------------*/
3576 static int
3577 FN_Next_Field(FORM *form)
3578 {
3579   T((T_CALLED("FN_Next_Field(%p)"), (void *)form));
3580   returnCode(_nc_Set_Current_Field(form,
3581                                    Next_Field_On_Page(form->current)));
3582 }
3583
3584 /*---------------------------------------------------------------------------
3585 |   Facility      :  libnform
3586 |   Function      :  static int FN_Previous_Field(FORM * form)
3587 |
3588 |   Description   :  Move to the previous field on the current page of the
3589 |                    form
3590 |
3591 |   Return Values :  E_OK                 - success
3592 |                    != E_OK              - error from subordinate call
3593 +--------------------------------------------------------------------------*/
3594 static int
3595 FN_Previous_Field(FORM *form)
3596 {
3597   T((T_CALLED("FN_Previous_Field(%p)"), (void *)form));
3598   returnCode(_nc_Set_Current_Field(form,
3599                                    Previous_Field_On_Page(form->current)));
3600 }
3601
3602 /*---------------------------------------------------------------------------
3603 |   Facility      :  libnform
3604 |   Function      :  static int FN_First_Field(FORM * form)
3605 |
3606 |   Description   :  Move to the first field on the current page of the form
3607 |
3608 |   Return Values :  E_OK                 - success
3609 |                    != E_OK              - error from subordinate call
3610 +--------------------------------------------------------------------------*/
3611 static int
3612 FN_First_Field(FORM *form)
3613 {
3614   T((T_CALLED("FN_First_Field(%p)"), (void *)form));
3615   returnCode(_nc_Set_Current_Field(form,
3616                                    Next_Field_On_Page(form->field[form->page[form->curpage].pmax])));
3617 }
3618
3619 /*---------------------------------------------------------------------------
3620 |   Facility      :  libnform
3621 |   Function      :  static int FN_Last_Field(FORM * form)
3622 |
3623 |   Description   :  Move to the last field on the current page of the form
3624 |
3625 |   Return Values :  E_OK                 - success
3626 |                    != E_OK              - error from subordinate call
3627 +--------------------------------------------------------------------------*/
3628 static int
3629 FN_Last_Field(FORM *form)
3630 {
3631   T((T_CALLED("FN_Last_Field(%p)"), (void *)form));
3632   returnCode(
3633               _nc_Set_Current_Field(form,
3634                                     Previous_Field_On_Page(form->field[form->page[form->curpage].pmin])));
3635 }
3636
3637 /*---------------------------------------------------------------------------
3638 |   Facility      :  libnform
3639 |   Function      :  static int FN_Sorted_Next_Field(FORM * form)
3640 |
3641 |   Description   :  Move to the sorted next field on the current page
3642 |                    of the form.
3643 |
3644 |   Return Values :  E_OK            - success
3645 |                    != E_OK         - error from subordinate call
3646 +--------------------------------------------------------------------------*/
3647 static int
3648 FN_Sorted_Next_Field(FORM *form)
3649 {
3650   T((T_CALLED("FN_Sorted_Next_Field(%p)"), (void *)form));
3651   returnCode(_nc_Set_Current_Field(form,
3652                                    Sorted_Next_Field(form->current)));
3653 }
3654
3655 /*---------------------------------------------------------------------------
3656 |   Facility      :  libnform
3657 |   Function      :  static int FN_Sorted_Previous_Field(FORM * form)
3658 |
3659 |   Description   :  Move to the sorted previous field on the current page
3660 |                    of the form.
3661 |
3662 |   Return Values :  E_OK            - success
3663 |                    != E_OK         - error from subordinate call
3664 +--------------------------------------------------------------------------*/
3665 static int
3666 FN_Sorted_Previous_Field(FORM *form)
3667 {
3668   T((T_CALLED("FN_Sorted_Previous_Field(%p)"), (void *)form));
3669   returnCode(_nc_Set_Current_Field(form,
3670                                    Sorted_Previous_Field(form->current)));
3671 }
3672
3673 /*---------------------------------------------------------------------------
3674 |   Facility      :  libnform
3675 |   Function      :  static int FN_Sorted_First_Field(FORM * form)
3676 |
3677 |   Description   :  Move to the sorted first field on the current page
3678 |                    of the form.
3679 |
3680 |   Return Values :  E_OK            - success
3681 |                    != E_OK         - error from subordinate call
3682 +--------------------------------------------------------------------------*/
3683 static int
3684 FN_Sorted_First_Field(FORM *form)
3685 {
3686   T((T_CALLED("FN_Sorted_First_Field(%p)"), (void *)form));
3687   returnCode(_nc_Set_Current_Field(form,
3688                                    Sorted_Next_Field(form->field[form->page[form->curpage].smax])));
3689 }
3690
3691 /*---------------------------------------------------------------------------
3692 |   Facility      :  libnform
3693 |   Function      :  static int FN_Sorted_Last_Field(FORM * form)
3694 |
3695 |   Description   :  Move to the sorted last field on the current page
3696 |                    of the form.
3697 |
3698 |   Return Values :  E_OK            - success
3699 |                    != E_OK         - error from subordinate call
3700 +--------------------------------------------------------------------------*/
3701 static int
3702 FN_Sorted_Last_Field(FORM *form)
3703 {
3704   T((T_CALLED("FN_Sorted_Last_Field(%p)"), (void *)form));
3705   returnCode(_nc_Set_Current_Field(form,
3706                                    Sorted_Previous_Field(form->field[form->page[form->curpage].smin])));
3707 }
3708
3709 /*---------------------------------------------------------------------------
3710 |   Facility      :  libnform
3711 |   Function      :  static int FN_Left_Field(FORM * form)
3712 |
3713 |   Description   :  Get the field on the left of the current field on the
3714 |                    same line and the same page. Cycles through the line.
3715 |
3716 |   Return Values :  E_OK            - success
3717 |                    != E_OK         - error from subordinate call
3718 +--------------------------------------------------------------------------*/
3719 static int
3720 FN_Left_Field(FORM *form)
3721 {
3722   T((T_CALLED("FN_Left_Field(%p)"), (void *)form));
3723   returnCode(_nc_Set_Current_Field(form,
3724                                    Left_Neighbor_Field(form->current)));
3725 }
3726
3727 /*---------------------------------------------------------------------------
3728 |   Facility      :  libnform
3729 |   Function      :  static int FN_Right_Field(FORM * form)
3730 |
3731 |   Description   :  Get the field on the right of the current field on the
3732 |                    same line and the same page. Cycles through the line.
3733 |
3734 |   Return Values :  E_OK            - success
3735 |                    != E_OK         - error from subordinate call
3736 +--------------------------------------------------------------------------*/
3737 static int
3738 FN_Right_Field(FORM *form)
3739 {
3740   T((T_CALLED("FN_Right_Field(%p)"), (void *)form));
3741   returnCode(_nc_Set_Current_Field(form,
3742                                    Right_Neighbor_Field(form->current)));
3743 }
3744
3745 /*---------------------------------------------------------------------------
3746 |   Facility      :  libnform
3747 |   Function      :  static int FN_Up_Field(FORM * form)
3748 |
3749 |   Description   :  Get the upper neighbor of the current field. This
3750 |                    cycles through the page. See the comments of the
3751 |                    Upper_Neighbor_Field function to understand how
3752 |                    'upper' is defined.
3753 |
3754 |   Return Values :  E_OK            - success
3755 |                    != E_OK         - error from subordinate call
3756 +--------------------------------------------------------------------------*/
3757 static int
3758 FN_Up_Field(FORM *form)
3759 {
3760   T((T_CALLED("FN_Up_Field(%p)"), (void *)form));
3761   returnCode(_nc_Set_Current_Field(form,
3762                                    Upper_Neighbor_Field(form->current)));
3763 }
3764
3765 /*---------------------------------------------------------------------------
3766 |   Facility      :  libnform
3767 |   Function      :  static int FN_Down_Field(FORM * form)
3768 |
3769 |   Description   :  Get the down neighbor of the current field. This
3770 |                    cycles through the page. See the comments of the
3771 |                    Down_Neighbor_Field function to understand how
3772 |                    'down' is defined.
3773 |
3774 |   Return Values :  E_OK            - success
3775 |                    != E_OK         - error from subordinate call
3776 +--------------------------------------------------------------------------*/
3777 static int
3778 FN_Down_Field(FORM *form)
3779 {
3780   T((T_CALLED("FN_Down_Field(%p)"), (void *)form));
3781   returnCode(_nc_Set_Current_Field(form,
3782                                    Down_Neighbor_Field(form->current)));
3783 }
3784 /*----------------------------------------------------------------------------
3785   END of Field Navigation routines
3786   --------------------------------------------------------------------------*/
3787
3788 /*----------------------------------------------------------------------------
3789   Helper routines for Page Navigation
3790   --------------------------------------------------------------------------*/
3791
3792 /*---------------------------------------------------------------------------
3793 |   Facility      :  libnform
3794 |   Function      :  int _nc_Set_Form_Page(FORM * form,
3795 |                                          int page,
3796 |                                          FIELD * field)
3797 |
3798 |   Description   :  Make the given page number the current page and make
3799 |                    the given field the current field on the page. If
3800 |                    for the field NULL is given, make the first field on
3801 |                    the page the current field. The routine acts only
3802 |                    if the requested page is not the current page.
3803 |
3804 |   Return Values :  E_OK                - success
3805 |                    != E_OK             - error from subordinate call
3806 |                    E_BAD_ARGUMENT      - invalid field pointer
3807 |                    E_SYSTEM_ERROR      - some severe basic error
3808 +--------------------------------------------------------------------------*/
3809 NCURSES_EXPORT(int)
3810 _nc_Set_Form_Page(FORM *form, int page, FIELD *field)
3811 {
3812   int res = E_OK;
3813
3814   if ((form->curpage != page))
3815     {
3816       FIELD *last_field, *field_on_page;
3817
3818       werase(Get_Form_Window(form));
3819       form->curpage = page;
3820       last_field = field_on_page = form->field[form->page[page].smin];
3821       do
3822         {
3823           if (field_on_page->opts & O_VISIBLE)
3824             if ((res = Display_Field(field_on_page)) != E_OK)
3825               return (res);
3826           field_on_page = field_on_page->snext;
3827         }
3828       while (field_on_page != last_field);
3829
3830       if (field)
3831         res = _nc_Set_Current_Field(form, field);
3832       else
3833         /* N.B.: we don't encapsulate this by Inter_Field_Navigation(),
3834            because this is already executed in a page navigation
3835            context that contains field navigation
3836          */
3837         res = FN_First_Field(form);
3838     }
3839   return (res);
3840 }
3841
3842 /*---------------------------------------------------------------------------
3843 |   Facility      :  libnform
3844 |   Function      :  static int Next_Page_Number(const FORM * form)
3845 |
3846 |   Description   :  Calculate the page number following the current page
3847 |                    number. This cycles if the highest page number is
3848 |                    reached.
3849 |
3850 |   Return Values :  The next page number
3851 +--------------------------------------------------------------------------*/
3852 NCURSES_INLINE static int
3853 Next_Page_Number(const FORM *form)
3854 {
3855   return (form->curpage + 1) % form->maxpage;
3856 }
3857
3858 /*---------------------------------------------------------------------------
3859 |   Facility      :  libnform
3860 |   Function      :  static int Previous_Page_Number(const FORM * form)
3861 |
3862 |   Description   :  Calculate the page number before the current page
3863 |                    number. This cycles if the first page number is
3864 |                    reached.
3865 |
3866 |   Return Values :  The previous page number
3867 +--------------------------------------------------------------------------*/
3868 NCURSES_INLINE static int
3869 Previous_Page_Number(const FORM *form)
3870 {
3871   return (form->curpage != 0 ? form->curpage - 1 : form->maxpage - 1);
3872 }
3873
3874 /*----------------------------------------------------------------------------
3875   Page Navigation routines
3876   --------------------------------------------------------------------------*/
3877
3878 /*---------------------------------------------------------------------------
3879 |   Facility      :  libnform
3880 |   Function      :  static int Page_Navigation(
3881 |                                               int (* const fct) (FORM *),
3882 |                                               FORM * form)
3883 |
3884 |   Description   :  Generic behavior for changing a page. This means
3885 |                    that the field is left and a new field is entered.
3886 |                    So the field must be validated and the field init/term
3887 |                    hooks must be called. Because also the page is changed,
3888 |                    the forms init/term hooks must be called also.
3889 |
3890 |   Return Values :  E_OK                - success
3891 |                    E_INVALID_FIELD     - field is invalid
3892 |                    some other          - error from subordinate call
3893 +--------------------------------------------------------------------------*/
3894 static int
3895 Page_Navigation(int (*const fct) (FORM *), FORM *form)
3896 {
3897   int res;
3898
3899   if (!_nc_Internal_Validation(form))
3900     res = E_INVALID_FIELD;
3901   else
3902     {
3903       Call_Hook(form, fieldterm);
3904       Call_Hook(form, formterm);
3905       res = fct(form);
3906       Call_Hook(form, forminit);
3907       Call_Hook(form, fieldinit);
3908     }
3909   return res;
3910 }
3911
3912 /*---------------------------------------------------------------------------
3913 |   Facility      :  libnform
3914 |   Function      :  static int PN_Next_Page(FORM * form)
3915 |
3916 |   Description   :  Move to the next page of the form
3917 |
3918 |   Return Values :  E_OK                - success
3919 |                    != E_OK             - error from subordinate call
3920 +--------------------------------------------------------------------------*/
3921 static int
3922 PN_Next_Page(FORM *form)
3923 {
3924   T((T_CALLED("PN_Next_Page(%p)"), (void *)form));
3925   returnCode(_nc_Set_Form_Page(form, Next_Page_Number(form), (FIELD *)0));
3926 }
3927
3928 /*---------------------------------------------------------------------------
3929 |   Facility      :  libnform
3930 |   Function      :  static int PN_Previous_Page(FORM * form)
3931 |
3932 |   Description   :  Move to the previous page of the form
3933 |
3934 |   Return Values :  E_OK              - success
3935 |                    != E_OK           - error from subordinate call
3936 +--------------------------------------------------------------------------*/
3937 static int
3938 PN_Previous_Page(FORM *form)
3939 {
3940   T((T_CALLED("PN_Previous_Page(%p)"), (void *)form));
3941   returnCode(_nc_Set_Form_Page(form, Previous_Page_Number(form), (FIELD *)0));
3942 }
3943
3944 /*---------------------------------------------------------------------------
3945 |   Facility      :  libnform
3946 |   Function      :  static int PN_First_Page(FORM * form)
3947 |
3948 |   Description   :  Move to the first page of the form
3949 |
3950 |   Return Values :  E_OK              - success
3951 |                    != E_OK           - error from subordinate call
3952 +--------------------------------------------------------------------------*/
3953 static int
3954 PN_First_Page(FORM *form)
3955 {
3956   T((T_CALLED("PN_First_Page(%p)"), (void *)form));
3957   returnCode(_nc_Set_Form_Page(form, 0, (FIELD *)0));
3958 }
3959
3960 /*---------------------------------------------------------------------------
3961 |   Facility      :  libnform
3962 |   Function      :  static int PN_Last_Page(FORM * form)
3963 |
3964 |   Description   :  Move to the last page of the form
3965 |
3966 |   Return Values :  E_OK              - success
3967 |                    != E_OK           - error from subordinate call
3968 +--------------------------------------------------------------------------*/
3969 static int
3970 PN_Last_Page(FORM *form)
3971 {
3972   T((T_CALLED("PN_Last_Page(%p)"), (void *)form));
3973   returnCode(_nc_Set_Form_Page(form, form->maxpage - 1, (FIELD *)0));
3974 }
3975
3976 /*----------------------------------------------------------------------------
3977   END of Field Navigation routines
3978   --------------------------------------------------------------------------*/
3979
3980 /*----------------------------------------------------------------------------
3981   Helper routines for the core form driver.
3982   --------------------------------------------------------------------------*/
3983
3984 /*---------------------------------------------------------------------------
3985 |   Facility      :  libnform
3986 |   Function      :  static int Data_Entry(FORM * form,int c)
3987 |
3988 |   Description   :  Enter character c into at the current position of the
3989 |                    current field of the form.
3990 |
3991 |   Return Values :  E_OK              - success
3992 |                    E_REQUEST_DENIED  - driver could not process the request
3993 |                    E_SYSTEM_ERROR    -
3994 +--------------------------------------------------------------------------*/
3995 static int
3996 Data_Entry(FORM *form, int c)
3997 {
3998   FIELD *field = form->current;
3999   int result = E_REQUEST_DENIED;
4000
4001   T((T_CALLED("Data_Entry(%p,%s)"), (void *)form, _tracechtype((chtype)c)));
4002   if ((field->opts & O_EDIT)
4003 #if FIX_FORM_INACTIVE_BUG
4004       && (field->opts & O_ACTIVE)
4005 #endif
4006     )
4007     {
4008       if ((field->opts & O_BLANK) &&
4009           First_Position_In_Current_Field(form) &&
4010           !(form->status & _FCHECK_REQUIRED) &&
4011           !(form->status & _WINDOW_MODIFIED))
4012         werase(form->w);
4013
4014       if (form->status & _OVLMODE)
4015         {
4016           waddch(form->w, (chtype)c);
4017         }
4018       else
4019         /* no _OVLMODE */
4020         {
4021           bool There_Is_Room = Is_There_Room_For_A_Char_In_Line(form);
4022
4023           if (!(There_Is_Room ||
4024                 ((Single_Line_Field(field) && Growable(field)))))
4025             RETURN(E_REQUEST_DENIED);
4026
4027           if (!There_Is_Room && !Field_Grown(field, 1))
4028             RETURN(E_SYSTEM_ERROR);
4029
4030           winsch(form->w, (chtype)c);
4031         }
4032
4033       if ((result = Wrapping_Not_Necessary_Or_Wrapping_Ok(form)) == E_OK)
4034         {
4035           bool End_Of_Field = (((field->drows - 1) == form->currow) &&
4036                                ((field->dcols - 1) == form->curcol));
4037
4038           form->status |= _WINDOW_MODIFIED;
4039           if (End_Of_Field && !Growable(field) && (field->opts & O_AUTOSKIP))
4040             result = Inter_Field_Navigation(FN_Next_Field, form);
4041           else
4042             {
4043               if (End_Of_Field && Growable(field) && !Field_Grown(field, 1))
4044                 result = E_SYSTEM_ERROR;
4045               else
4046                 {
4047 #if USE_WIDEC_SUPPORT
4048                   /*
4049                    * We have just added a byte to the form field.  It may have
4050                    * been part of a multibyte character.  If it was, the
4051                    * addch_used field is nonzero and we should not try to move
4052                    * to a new column.
4053                    */
4054                   if (WINDOW_EXT(form->w, addch_used) == 0)
4055                     IFN_Next_Character(form);
4056 #else
4057                   IFN_Next_Character(form);
4058 #endif
4059                   result = E_OK;
4060                 }
4061             }
4062         }
4063     }
4064   RETURN(result);
4065 }
4066
4067 /* Structure to describe the binding of a request code to a function.
4068    The member keycode codes the request value as well as the generic
4069    routine to use for the request. The code for the generic routine
4070    is coded in the upper 16 Bits while the request code is coded in
4071    the lower 16 bits.
4072
4073    In terms of C++ you might think of a request as a class with a
4074    virtual method "perform". The different types of request are
4075    derived from this base class and overload (or not) the base class
4076    implementation of perform.
4077 */
4078 typedef struct
4079 {
4080   int keycode;                  /* must be at least 32 bit: hi:mode, lo: key */
4081   int (*cmd) (FORM *);          /* low level driver routine for this key     */
4082 }
4083 Binding_Info;
4084
4085 /* You may see this is the class-id of the request type class */
4086 #define ID_PN    (0x00000000)   /* Page navigation           */
4087 #define ID_FN    (0x00010000)   /* Inter-Field navigation    */
4088 #define ID_IFN   (0x00020000)   /* Intra-Field navigation    */
4089 #define ID_VSC   (0x00030000)   /* Vertical Scrolling        */
4090 #define ID_HSC   (0x00040000)   /* Horizontal Scrolling      */
4091 #define ID_FE    (0x00050000)   /* Field Editing             */
4092 #define ID_EM    (0x00060000)   /* Edit Mode                 */
4093 #define ID_FV    (0x00070000)   /* Field Validation          */
4094 #define ID_CH    (0x00080000)   /* Choice                    */
4095 #define ID_Mask  (0xffff0000)
4096 #define Key_Mask (0x0000ffff)
4097 #define ID_Shft  (16)
4098
4099 /* This array holds all the Binding Infos */
4100 /* *INDENT-OFF* */
4101 static const Binding_Info bindings[MAX_FORM_COMMAND - MIN_FORM_COMMAND + 1] =
4102 {
4103   { REQ_NEXT_PAGE    |ID_PN  ,PN_Next_Page},
4104   { REQ_PREV_PAGE    |ID_PN  ,PN_Previous_Page},
4105   { REQ_FIRST_PAGE   |ID_PN  ,PN_First_Page},
4106   { REQ_LAST_PAGE    |ID_PN  ,PN_Last_Page},
4107
4108   { REQ_NEXT_FIELD   |ID_FN  ,FN_Next_Field},
4109   { REQ_PREV_FIELD   |ID_FN  ,FN_Previous_Field},
4110   { REQ_FIRST_FIELD  |ID_FN  ,FN_First_Field},
4111   { REQ_LAST_FIELD   |ID_FN  ,FN_Last_Field},
4112   { REQ_SNEXT_FIELD  |ID_FN  ,FN_Sorted_Next_Field},
4113   { REQ_SPREV_FIELD  |ID_FN  ,FN_Sorted_Previous_Field},
4114   { REQ_SFIRST_FIELD |ID_FN  ,FN_Sorted_First_Field},
4115   { REQ_SLAST_FIELD  |ID_FN  ,FN_Sorted_Last_Field},
4116   { REQ_LEFT_FIELD   |ID_FN  ,FN_Left_Field},
4117   { REQ_RIGHT_FIELD  |ID_FN  ,FN_Right_Field},
4118   { REQ_UP_FIELD     |ID_FN  ,FN_Up_Field},
4119   { REQ_DOWN_FIELD   |ID_FN  ,FN_Down_Field},
4120
4121   { REQ_NEXT_CHAR    |ID_IFN ,IFN_Next_Character},
4122   { REQ_PREV_CHAR    |ID_IFN ,IFN_Previous_Character},
4123   { REQ_NEXT_LINE    |ID_IFN ,IFN_Next_Line},
4124   { REQ_PREV_LINE    |ID_IFN ,IFN_Previous_Line},
4125   { REQ_NEXT_WORD    |ID_IFN ,IFN_Next_Word},
4126   { REQ_PREV_WORD    |ID_IFN ,IFN_Previous_Word},
4127   { REQ_BEG_FIELD    |ID_IFN ,IFN_Beginning_Of_Field},
4128   { REQ_END_FIELD    |ID_IFN ,IFN_End_Of_Field},
4129   { REQ_BEG_LINE     |ID_IFN ,IFN_Beginning_Of_Line},
4130   { REQ_END_LINE     |ID_IFN ,IFN_End_Of_Line},
4131   { REQ_LEFT_CHAR    |ID_IFN ,IFN_Left_Character},
4132   { REQ_RIGHT_CHAR   |ID_IFN ,IFN_Right_Character},
4133   { REQ_UP_CHAR      |ID_IFN ,IFN_Up_Character},
4134   { REQ_DOWN_CHAR    |ID_IFN ,IFN_Down_Character},
4135
4136   { REQ_NEW_LINE     |ID_FE  ,FE_New_Line},
4137   { REQ_INS_CHAR     |ID_FE  ,FE_Insert_Character},
4138   { REQ_INS_LINE     |ID_FE  ,FE_Insert_Line},
4139   { REQ_DEL_CHAR     |ID_FE  ,FE_Delete_Character},
4140   { REQ_DEL_PREV     |ID_FE  ,FE_Delete_Previous},
4141   { REQ_DEL_LINE     |ID_FE  ,FE_Delete_Line},
4142   { REQ_DEL_WORD     |ID_FE  ,FE_Delete_Word},
4143   { REQ_CLR_EOL      |ID_FE  ,FE_Clear_To_End_Of_Line},
4144   { REQ_CLR_EOF      |ID_FE  ,FE_Clear_To_End_Of_Field},
4145   { REQ_CLR_FIELD    |ID_FE  ,FE_Clear_Field},
4146
4147   { REQ_OVL_MODE     |ID_EM  ,EM_Overlay_Mode},
4148   { REQ_INS_MODE     |ID_EM  ,EM_Insert_Mode},
4149
4150   { REQ_SCR_FLINE    |ID_VSC ,VSC_Scroll_Line_Forward},
4151   { REQ_SCR_BLINE    |ID_VSC ,VSC_Scroll_Line_Backward},
4152   { REQ_SCR_FPAGE    |ID_VSC ,VSC_Scroll_Page_Forward},
4153   { REQ_SCR_BPAGE    |ID_VSC ,VSC_Scroll_Page_Backward},
4154   { REQ_SCR_FHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Forward},
4155   { REQ_SCR_BHPAGE   |ID_VSC ,VSC_Scroll_Half_Page_Backward},
4156
4157   { REQ_SCR_FCHAR    |ID_HSC ,HSC_Scroll_Char_Forward},
4158   { REQ_SCR_BCHAR    |ID_HSC ,HSC_Scroll_Char_Backward},
4159   { REQ_SCR_HFLINE   |ID_HSC ,HSC_Horizontal_Line_Forward},
4160   { REQ_SCR_HBLINE   |ID_HSC ,HSC_Horizontal_Line_Backward},
4161   { REQ_SCR_HFHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Forward},
4162   { REQ_SCR_HBHALF   |ID_HSC ,HSC_Horizontal_Half_Line_Backward},
4163
4164   { REQ_VALIDATION   |ID_FV  ,FV_Validation},
4165
4166   { REQ_NEXT_CHOICE  |ID_CH  ,CR_Next_Choice},
4167   { REQ_PREV_CHOICE  |ID_CH  ,CR_Previous_Choice}
4168 };
4169 /* *INDENT-ON* */
4170
4171 /*---------------------------------------------------------------------------
4172 |   Facility      :  libnform
4173 |   Function      :  int form_driver(FORM * form,int  c)
4174 |
4175 |   Description   :  This is the workhorse of the forms system. It checks
4176 |                    to determine whether the character c is a request or
4177 |                    data. If it is a request, the form driver executes
4178 |                    the request and returns the result. If it is data
4179 |                    (printable character), it enters the data into the
4180 |                    current position in the current field. If it is not
4181 |                    recognized, the form driver assumes it is an application
4182 |                    defined command and returns E_UNKNOWN_COMMAND.
4183 |                    Application defined command should be defined relative
4184 |                    to MAX_FORM_COMMAND, the maximum value of a request.
4185 |
4186 |   Return Values :  E_OK              - success
4187 |                    E_SYSTEM_ERROR    - system error
4188 |                    E_BAD_ARGUMENT    - an argument is incorrect
4189 |                    E_NOT_POSTED      - form is not posted
4190 |                    E_INVALID_FIELD   - field contents are invalid
4191 |                    E_BAD_STATE       - called from inside a hook routine
4192 |                    E_REQUEST_DENIED  - request failed
4193 |                    E_NOT_CONNECTED   - no fields are connected to the form
4194 |                    E_UNKNOWN_COMMAND - command not known
4195 +--------------------------------------------------------------------------*/
4196 NCURSES_EXPORT(int)
4197 form_driver(FORM *form, int c)
4198 {
4199   const Binding_Info *BI = (Binding_Info *) 0;
4200   int res = E_UNKNOWN_COMMAND;
4201
4202   T((T_CALLED("form_driver(%p,%d)"), (void *)form, c));
4203
4204   if (!form)
4205     RETURN(E_BAD_ARGUMENT);
4206
4207   if (!(form->field))
4208     RETURN(E_NOT_CONNECTED);
4209
4210   assert(form->page);
4211
4212   if (c == FIRST_ACTIVE_MAGIC)
4213     {
4214       form->current = _nc_First_Active_Field(form);
4215       RETURN(E_OK);
4216     }
4217
4218   assert(form->current &&
4219          form->current->buf &&
4220          (form->current->form == form)
4221     );
4222
4223   if (form->status & _IN_DRIVER)
4224     RETURN(E_BAD_STATE);
4225
4226   if (!(form->status & _POSTED))
4227     RETURN(E_NOT_POSTED);
4228
4229   if ((c >= MIN_FORM_COMMAND && c <= MAX_FORM_COMMAND) &&
4230       ((bindings[c - MIN_FORM_COMMAND].keycode & Key_Mask) == c))
4231     BI = &(bindings[c - MIN_FORM_COMMAND]);
4232
4233   if (BI)
4234     {
4235       typedef int (*Generic_Method) (int (*const) (FORM *), FORM *);
4236       static const Generic_Method Generic_Methods[] =
4237       {
4238         Page_Navigation,        /* overloaded to call field&form hooks */
4239         Inter_Field_Navigation, /* overloaded to call field hooks      */
4240         NULL,                   /* Intra-Field is generic              */
4241         Vertical_Scrolling,     /* Overloaded to check multi-line      */
4242         Horizontal_Scrolling,   /* Overloaded to check single-line     */
4243         Field_Editing,          /* Overloaded to mark modification     */
4244         NULL,                   /* Edit Mode is generic                */
4245         NULL,                   /* Field Validation is generic         */
4246         NULL                    /* Choice Request is generic           */
4247       };
4248       size_t nMethods = (sizeof(Generic_Methods) / sizeof(Generic_Methods[0]));
4249       size_t method = (BI->keycode >> ID_Shft) & 0xffff;        /* see ID_Mask */
4250
4251       if ((method >= nMethods) || !(BI->cmd))
4252         res = E_SYSTEM_ERROR;
4253       else
4254         {
4255           Generic_Method fct = Generic_Methods[method];
4256
4257           if (fct)
4258             res = fct(BI->cmd, form);
4259           else
4260             res = (BI->cmd) (form);
4261         }
4262     }
4263 #ifdef NCURSES_MOUSE_VERSION
4264   else if (KEY_MOUSE == c)
4265     {
4266       MEVENT event;
4267       WINDOW *win = form->win ? form->win : StdScreen(Get_Form_Screen(form));
4268       WINDOW *sub = form->sub ? form->sub : win;
4269
4270       getmouse(&event);
4271       if ((event.bstate & (BUTTON1_CLICKED |
4272                            BUTTON1_DOUBLE_CLICKED |
4273                            BUTTON1_TRIPLE_CLICKED))
4274           && wenclose(win, event.y, event.x))
4275         {                       /* we react only if the click was in the userwin, that means
4276                                  * inside the form display area or at the decoration window.
4277                                  */
4278           int ry = event.y, rx = event.x;       /* screen coordinates */
4279
4280           res = E_REQUEST_DENIED;
4281           if (mouse_trafo(&ry, &rx, FALSE))
4282             {                   /* rx, ry are now "curses" coordinates */
4283               if (ry < sub->_begy)
4284                 {               /* we clicked above the display region; this is
4285                                  * interpreted as "scroll up" request
4286                                  */
4287                   if (event.bstate & BUTTON1_CLICKED)
4288                     res = form_driver(form, REQ_PREV_FIELD);
4289                   else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4290                     res = form_driver(form, REQ_PREV_PAGE);
4291                   else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4292                     res = form_driver(form, REQ_FIRST_FIELD);
4293                 }
4294               else if (ry > sub->_begy + sub->_maxy)
4295                 {               /* we clicked below the display region; this is
4296                                  * interpreted as "scroll down" request
4297                                  */
4298                   if (event.bstate & BUTTON1_CLICKED)
4299                     res = form_driver(form, REQ_NEXT_FIELD);
4300                   else if (event.bstate & BUTTON1_DOUBLE_CLICKED)
4301                     res = form_driver(form, REQ_NEXT_PAGE);
4302                   else if (event.bstate & BUTTON1_TRIPLE_CLICKED)
4303                     res = form_driver(form, REQ_LAST_FIELD);
4304                 }
4305               else if (wenclose(sub, event.y, event.x))
4306                 {               /* Inside the area we try to find the hit item */
4307                   int i;
4308
4309                   ry = event.y;
4310                   rx = event.x;
4311                   if (wmouse_trafo(sub, &ry, &rx, FALSE))
4312                     {
4313                       int min_field = form->page[form->curpage].pmin;
4314                       int max_field = form->page[form->curpage].pmax;
4315
4316                       for (i = min_field; i <= max_field; ++i)
4317                         {
4318                           FIELD *field = form->field[i];
4319
4320                           if (Field_Is_Selectable(field)
4321                               && Field_encloses(field, ry, rx) == E_OK)
4322                             {
4323                               res = _nc_Set_Current_Field(form, field);
4324                               if (res == E_OK)
4325                                 res = _nc_Position_Form_Cursor(form);
4326                               if (res == E_OK
4327                                   && (event.bstate & BUTTON1_DOUBLE_CLICKED))
4328                                 res = E_UNKNOWN_COMMAND;
4329                               break;
4330                             }
4331                         }
4332                     }
4333                 }
4334             }
4335         }
4336       else
4337         res = E_REQUEST_DENIED;
4338     }
4339 #endif /* NCURSES_MOUSE_VERSION */
4340   else if (!(c & (~(int)MAX_REGULAR_CHARACTER)))
4341     {
4342       /*
4343        * If we're using 8-bit characters, iscntrl+isprint cover the whole set.
4344        * But with multibyte characters, there is a third possibility, i.e.,
4345        * parts of characters that build up into printable characters which are
4346        * not considered printable.
4347        *
4348        * FIXME: the wide-character branch should also use Check_Char().
4349        */
4350 #if USE_WIDEC_SUPPORT
4351       if (!iscntrl(UChar(c)))
4352 #else
4353       if (isprint(UChar(c)) &&
4354           Check_Char(form, form->current, form->current->type, c,
4355                      (TypeArgument *)(form->current->arg)))
4356 #endif
4357         res = Data_Entry(form, c);
4358     }
4359   _nc_Refresh_Current_Field(form);
4360   RETURN(res);
4361 }
4362
4363 /*----------------------------------------------------------------------------
4364   Field-Buffer manipulation routines.
4365   The effects of setting a buffer are tightly coupled to the core of the form
4366   driver logic. This is especially true in the case of growable fields.
4367   So I don't separate this into a separate module.
4368   --------------------------------------------------------------------------*/
4369
4370 /*---------------------------------------------------------------------------
4371 |   Facility      :  libnform
4372 |   Function      :  int set_field_buffer(FIELD *field,
4373 |                                         int buffer, char *value)
4374 |
4375 |   Description   :  Set the given buffer of the field to the given value.
4376 |                    Buffer 0 stores the displayed content of the field.
4377 |                    For dynamic fields this may grow the fieldbuffers if
4378 |                    the length of the value exceeds the current buffer
4379 |                    length. For buffer 0 only printable values are allowed.
4380 |                    For static fields, the value needs not to be zero ter-
4381 |                    minated. It is copied up to the length of the buffer.
4382 |
4383 |   Return Values :  E_OK            - success
4384 |                    E_BAD_ARGUMENT  - invalid argument
4385 |                    E_SYSTEM_ERROR  - system error
4386 +--------------------------------------------------------------------------*/
4387 NCURSES_EXPORT(int)
4388 set_field_buffer(FIELD *field, int buffer, const char *value)
4389 {
4390   FIELD_CELL *p;
4391   int res = E_OK;
4392   unsigned int i;
4393   unsigned int len;
4394
4395 #if USE_WIDEC_SUPPORT
4396   FIELD_CELL *widevalue = 0;
4397 #endif
4398
4399   T((T_CALLED("set_field_buffer(%p,%d,%s)"), (void *)field, buffer, _nc_visbuf(value)));
4400
4401   if (!field || !value || ((buffer < 0) || (buffer > field->nbuf)))
4402     RETURN(E_BAD_ARGUMENT);
4403
4404   len = Buffer_Length(field);
4405
4406   if (Growable(field))
4407     {
4408       /* for a growable field we must assume zero terminated strings, because
4409          somehow we have to detect the length of what should be copied.
4410        */
4411       unsigned int vlen = strlen(value);
4412
4413       if (vlen > len)
4414         {
4415           if (!Field_Grown(field,
4416                            (int)(1 + (vlen - len) / ((field->rows + field->nrow)
4417                                                      * field->cols))))
4418             RETURN(E_SYSTEM_ERROR);
4419
4420           len = vlen;
4421         }
4422     }
4423
4424   p = Address_Of_Nth_Buffer(field, buffer);
4425
4426 #if USE_WIDEC_SUPPORT
4427   /*
4428    * Use addstr's logic for converting a string to an array of cchar_t's.
4429    * There should be a better way, but this handles nonspacing characters
4430    * and other special cases that we really do not want to handle here.
4431    */
4432 #if NCURSES_EXT_FUNCS
4433   if (wresize(field->working, 1, Buffer_Length(field) + 1) == ERR)
4434 #endif
4435     {
4436       delwin(field->working);
4437       field->working = newpad(1, Buffer_Length(field) + 1);
4438     }
4439   len = Buffer_Length(field);
4440   wclear(field->working);
4441   mvwaddstr(field->working, 0, 0, value);
4442
4443   if ((widevalue = typeCalloc(FIELD_CELL, len + 1)) == 0)
4444     {
4445       RETURN(E_SYSTEM_ERROR);
4446     }
4447   else
4448     {
4449       for (i = 0; i < (unsigned)field->drows; ++i)
4450         {
4451           mvwin_wchnstr(field->working, 0, i * field->dcols,
4452                         widevalue + (i * field->dcols),
4453                         field->dcols);
4454         }
4455       for (i = 0; i < len; ++i)
4456         {
4457           if (CharEq(myZEROS, widevalue[i]))
4458             {
4459               while (i < len)
4460                 p[i++] = myBLANK;
4461               break;
4462             }
4463           p[i] = widevalue[i];
4464         }
4465       free(widevalue);
4466     }
4467 #else
4468   for (i = 0; i < len; ++i)
4469     {
4470       if (value[i] == '\0')
4471         {
4472           while (i < len)
4473             p[i++] = myBLANK;
4474           break;
4475         }
4476       p[i] = value[i];
4477     }
4478 #endif
4479
4480   if (buffer == 0)
4481     {
4482       int syncres;
4483
4484       if (((syncres = Synchronize_Field(field)) != E_OK) &&
4485           (res == E_OK))
4486         res = syncres;
4487       if (((syncres = Synchronize_Linked_Fields(field)) != E_OK) &&
4488           (res == E_OK))
4489         res = syncres;
4490     }
4491   RETURN(res);
4492 }
4493
4494 /*---------------------------------------------------------------------------
4495 |   Facility      :  libnform
4496 |   Function      :  char *field_buffer(const FIELD *field,int buffer)
4497 |
4498 |   Description   :  Return the address of the buffer for the field.
4499 |
4500 |   Return Values :  Pointer to buffer or NULL if arguments were invalid.
4501 +--------------------------------------------------------------------------*/
4502 NCURSES_EXPORT(char *)
4503 field_buffer(const FIELD *field, int buffer)
4504 {
4505   char *result = 0;
4506
4507   T((T_CALLED("field_buffer(%p,%d)"), (const void *)field, buffer));
4508
4509   if (field && (buffer >= 0) && (buffer <= field->nbuf))
4510     {
4511 #if USE_WIDEC_SUPPORT
4512       FIELD_CELL *data = Address_Of_Nth_Buffer(field, buffer);
4513       unsigned need = 0;
4514       int size = Buffer_Length(field);
4515       int n;
4516
4517       /* determine the number of bytes needed to store the expanded string */
4518       for (n = 0; n < size; ++n)
4519         {
4520           if (!isWidecExt(data[n]))
4521             {
4522               mbstate_t state;
4523               size_t next;
4524
4525               init_mb(state);
4526               next = _nc_wcrtomb(0, data[n].chars[0], &state);
4527               if (!isEILSEQ(next))
4528                 need += next;
4529             }
4530         }
4531
4532       /* allocate a place to store the expanded string */
4533       if (field->expanded[buffer] != 0)
4534         free(field->expanded[buffer]);
4535       field->expanded[buffer] = typeMalloc(char, need + 1);
4536
4537       /* expand the multibyte data */
4538       if ((result = field->expanded[buffer]) != 0)
4539         {
4540           wclear(field->working);
4541           mvwadd_wchnstr(field->working, 0, 0, data, size);
4542           mvwinnstr(field->working, 0, 0, result, (int)need);
4543         }
4544 #else
4545       result = Address_Of_Nth_Buffer(field, buffer);
4546 #endif
4547     }
4548   returnPtr(result);
4549 }
4550
4551 #if USE_WIDEC_SUPPORT
4552
4553 /*---------------------------------------------------------------------------
4554 | Convert a multibyte string to a wide-character string.  The result must be
4555 | freed by the caller.
4556 +--------------------------------------------------------------------------*/
4557 NCURSES_EXPORT(wchar_t *)
4558 _nc_Widen_String(char *source, int *lengthp)
4559 {
4560   wchar_t *result = 0;
4561   wchar_t wch;
4562   size_t given = strlen(source);
4563   size_t tries;
4564   int pass;
4565   int status;
4566
4567 #ifndef state_unused
4568   mbstate_t state;
4569 #endif
4570
4571   for (pass = 0; pass < 2; ++pass)
4572     {
4573       unsigned need = 0;
4574       size_t passed = 0;
4575
4576       while (passed < given)
4577         {
4578           bool found = FALSE;
4579
4580           for (tries = 1, status = 0; tries <= (given - passed); ++tries)
4581             {
4582               int save = source[passed + tries];
4583
4584               source[passed + tries] = 0;
4585               reset_mbytes(state);
4586               status = check_mbytes(wch, source + passed, tries, state);
4587               source[passed + tries] = (char)save;
4588
4589               if (status > 0)
4590                 {
4591                   found = TRUE;
4592                   break;
4593                 }
4594             }
4595           if (found)
4596             {
4597               if (pass)
4598                 {
4599                   result[need] = wch;
4600                 }
4601               passed += status;
4602               ++need;
4603             }
4604           else
4605             {
4606               if (pass)
4607                 {
4608                   result[need] = source[passed];
4609                 }
4610               ++need;
4611               ++passed;
4612             }
4613         }
4614
4615       if (!pass)
4616         {
4617           if (!need)
4618             break;
4619           result = typeCalloc(wchar_t, need);
4620
4621           *lengthp = need;
4622           if (result == 0)
4623             break;
4624         }
4625     }
4626
4627   return result;
4628 }
4629 #endif
4630
4631 /* frm_driver.c ends here */