Home | History | Annotate | Line # | Download | only in libform
internals.c revision 1.14
      1 /*	$NetBSD: internals.c,v 1.14 2001/04/06 05:03:22 blymn Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998-1999 Brett Lymn
      5  *                         (blymn (at) baea.com.au, brett_lymn (at) yahoo.com.au)
      6  * All rights reserved.
      7  *
      8  * This code has been donated to The NetBSD Foundation by the Author.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. The name of the author may not be used to endorse or promote products
     16  *    derived from this software withough specific prior written permission
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  *
     29  *
     30  */
     31 
     32 #include <ctype.h>
     33 #include <stdio.h>
     34 #include <stdlib.h>
     35 #include <strings.h>
     36 #include "internals.h"
     37 #include "form.h"
     38 
     39 #ifdef DEBUG
     40 /*
     41  *  file handle to write debug info to, this will be initialised when
     42  *  the form is first posted.
     43  */
     44 FILE *dbg = NULL;
     45 #endif
     46 
     47 /* define our own min function - this is not generic but will do here
     48  * (don't believe me?  think about what value you would get
     49  * from min(x++, y++)
     50  */
     51 #define min(a,b) (((a) > (b))? (b) : (a))
     52 
     53 /* for the line joining function... */
     54 #define JOIN_NEXT    1
     55 #define JOIN_NEXT_NW 2 /* next join, don't wrap the joined line */
     56 #define JOIN_PREV    3
     57 #define JOIN_PREV_NW 4 /* previous join, don't wrap the joined line */
     58 
     59 static void
     60 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val);
     61 static void
     62 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val);
     63 static int
     64 _formi_join_line(FIELD *field, char *str, unsigned int pos, int direction);
     65 void
     66 _formi_hscroll_back(FIELD *field, unsigned int amt);
     67 void
     68 _formi_hscroll_fwd(FIELD *field, unsigned int amt);
     69 static void
     70 _formi_scroll_back(FIELD *field, unsigned int amt);
     71 static void
     72 _formi_scroll_fwd(FIELD *field, unsigned int amt);
     73 static int
     74 find_sow(char *str, unsigned int offset);
     75 static int
     76 find_cur_line(FIELD *cur);
     77 
     78 /*
     79  * Open the debug file if it is not already open....
     80  */
     81 #ifdef DEBUG
     82 int
     83 _formi_create_dbg_file(void)
     84 {
     85 	if (dbg == NULL) {
     86 		dbg = fopen("___form_dbg.out", "w");
     87 		if (dbg == NULL) {
     88 			fprintf(stderr, "Cannot open debug file!\n");
     89 			return E_SYSTEM_ERROR;
     90 		}
     91 	}
     92 
     93 	return E_OK;
     94 }
     95 #endif
     96 
     97 /*
     98  * Set the form's current field to the first valid field on the page.
     99  * Assume the fields have been sorted and stitched.
    100  */
    101 int
    102 _formi_pos_first_field(FORM *form)
    103 {
    104 	FIELD *cur;
    105 	int old_page;
    106 
    107 	old_page = form->page;
    108 
    109 	  /* scan forward for an active page....*/
    110 	while (form->page_starts[form->page].in_use == 0) {
    111 		form->page++;
    112 		if (form->page > form->max_page) {
    113 			form->page = old_page;
    114 			return E_REQUEST_DENIED;
    115 		}
    116 	}
    117 
    118 	  /* then scan for a field we can use */
    119 	cur = form->fields[form->page_starts[form->page].first];
    120 	while ((cur->opts & (O_VISIBLE | O_ACTIVE))
    121 	       != (O_VISIBLE | O_ACTIVE)) {
    122 		cur = CIRCLEQ_NEXT(cur, glue);
    123 		if (cur == (void *) &form->sorted_fields) {
    124 			form->page = old_page;
    125 			return E_REQUEST_DENIED;
    126 		}
    127 	}
    128 
    129 	form->cur_field = cur->index;
    130 	return E_OK;
    131 }
    132 
    133 /*
    134  * Set the field to the next active and visible field, the fields are
    135  * traversed in index order in the direction given.  If the parameter
    136  * use_sorted is TRUE then the sorted field list will be traversed instead
    137  * of using the field index.
    138  */
    139 int
    140 _formi_pos_new_field(FORM *form, unsigned direction, unsigned use_sorted)
    141 {
    142 	FIELD *cur;
    143 	int i;
    144 
    145 	i = form->cur_field;
    146 	cur = form->fields[i];
    147 
    148 	do {
    149 		if (direction == _FORMI_FORWARD) {
    150 			if (use_sorted == TRUE) {
    151 				if ((form->wrap == FALSE) &&
    152 				    (cur == CIRCLEQ_LAST(&form->sorted_fields)))
    153 					return E_REQUEST_DENIED;
    154 				cur = CIRCLEQ_NEXT(cur, glue);
    155 				i = cur->index;
    156 			} else {
    157 				if ((form->wrap == FALSE) &&
    158 				    ((i + 1) >= form->field_count))
    159 					return E_REQUEST_DENIED;
    160 				i++;
    161 				if (i >= form->field_count)
    162 					i = 0;
    163 			}
    164 		} else {
    165 			if (use_sorted == TRUE) {
    166 				if ((form->wrap == FALSE) &&
    167 				    (cur == CIRCLEQ_FIRST(&form->sorted_fields)))
    168 					return E_REQUEST_DENIED;
    169 				cur = CIRCLEQ_PREV(cur, glue);
    170 				i = cur->index;
    171 			} else {
    172 				if ((form->wrap == FALSE) && (i <= 0))
    173 					return E_REQUEST_DENIED;
    174 				i--;
    175 				if (i < 0)
    176 					i = form->field_count - 1;
    177 			}
    178 		}
    179 
    180 		if ((form->fields[i]->opts & (O_VISIBLE | O_ACTIVE))
    181 			== (O_VISIBLE | O_ACTIVE)) {
    182 			form->cur_field = i;
    183 			return E_OK;
    184 		}
    185 	}
    186 	while (i != form->cur_field);
    187 
    188 	return E_REQUEST_DENIED;
    189 }
    190 
    191 /*
    192  * Find the line in a field that the cursor is currently on.
    193  */
    194 static int
    195 find_cur_line(FIELD *cur)
    196 {
    197 	unsigned start, end, pos, row;
    198 	const char *str;
    199 
    200 	str = cur->buffers[0].string;
    201 	pos = cur->start_char + cur->cursor_xpos;
    202 
    203 	start = 0;
    204 	end = 0;
    205 
    206 	for (row = 1; row < cur->row_count; row++) {
    207 		start = _formi_find_bol(str, start);
    208 		end = _formi_find_eol(str, end);
    209 		if ((pos >= start) && (pos <= end))
    210 			return row;
    211 	}
    212 
    213 	return 0;
    214 }
    215 
    216 
    217 /*
    218  * Word wrap the contents of the field's buffer 0 if this is allowed.
    219  * If the wrap is successful, that is, the row count nor the buffer
    220  * size is exceeded then the function will return E_OK, otherwise it
    221  * will return E_REQUEST_DENIED.
    222  */
    223 int
    224 _formi_wrap_field(FIELD *field, unsigned int pos)
    225 {
    226 	char *str, *new;
    227 	int width, length, allocated, row_count, sol, eol, wrapped;
    228 	size_t new_size;
    229 
    230 	wrapped = FALSE;
    231 	row_count = 0;
    232 	allocated = field->buffers[0].allocated;
    233 	length = field->buffers[0].length;
    234 	if ((str = (char *) malloc(sizeof(char) * allocated)) == NULL)
    235 		return E_SYSTEM_ERROR;
    236 
    237 	strcpy(str,field->buffers[0].string);
    238 
    239 	if ((field->opts & O_STATIC) == O_STATIC) {
    240 		width = field->cols + 1;
    241 		if ((field->rows + field->nrows) == 1)
    242 			return E_OK; /* cannot wrap a single line */
    243 	} else {
    244 		if ((field->drows + field->nrows) == 1)
    245 			return E_OK;
    246 		width = field->dcols;
    247 	}
    248 
    249 	while (str[pos] != '\0') {
    250 		row_count++;
    251 		sol = _formi_find_bol(str, pos);
    252 		eol = _formi_find_eol(str, pos);
    253 		if ((eol - sol) <= width) {
    254 			  /* line may be too short, try joining some lines */
    255 			pos = eol;
    256 			if ((eol - sol) == width) {
    257 				/* if line is just right then don't wrap */
    258 				pos++;
    259 				continue;
    260 			}
    261 
    262 			if (_formi_join_line(field, str, pos, JOIN_NEXT_NW)
    263 			    == E_OK) {
    264 				row_count--; /* cuz we just joined a line */
    265 				wrapped = TRUE;
    266 			} else
    267 				break;
    268 		} else {
    269 			  /* line is too long, split it - maybe */
    270 			  /* split on first whitespace before current word */
    271 			pos = sol + width;
    272 			if ((!isblank(str[pos])) &&
    273 			    ((field->opts & O_WRAP) == O_WRAP))
    274 				pos = find_sow(str, pos);
    275 
    276 			if (pos != sol) {
    277 				if (length + 1 >= allocated) {
    278 					new_size = allocated + 64
    279 						- (allocated % 64);
    280 
    281 					if ((new = (char *) realloc(str,
    282 								    sizeof(char) * new_size)
    283 					     ) == NULL) {
    284 						free(str);
    285 						return E_SYSTEM_ERROR;
    286 					}
    287 					str = new;
    288 					allocated = new_size;
    289 				}
    290 
    291 				bcopy(&str[pos], &str[pos + 1],
    292 				      (unsigned) length - pos - 1);
    293 				str[pos] = '\n';
    294 				pos = pos + 1;
    295 				length++;
    296 				wrapped = TRUE;
    297 			} else
    298 				break;
    299 		}
    300 	}
    301 
    302 	if (row_count > field->rows) {
    303 		free(str);
    304 		return E_REQUEST_DENIED;
    305 	}
    306 
    307 	if (wrapped == TRUE) {
    308 		field->buffers[0].length = length;
    309 		field->buffers[0].allocated = allocated;
    310 		free(field->buffers[0].string);
    311 		field->buffers[0].string = str;
    312 	} else /* all that work was in vain.... */
    313 		free(str);
    314 
    315 	return E_OK;
    316 }
    317 
    318 /*
    319  * Join the two lines that surround the location pos, the type
    320  * variable indicates the direction of the join.  Note that pos is
    321  * assumed to be at either the end of the line for a JOIN_NEXT or at
    322  * the beginning of the line for a JOIN_PREV.  We need to check the
    323  * field options to ensure the join does not overflow the line limit
    324  * (if wrap is off) or wrap the field buffer again.  Returns E_OK if
    325  * the join was successful or E_REQUEST_DENIED if the join cannot
    326  * happen.
    327  */
    328 static int
    329 _formi_join_line(FIELD *field, char *str, unsigned int pos, int direction)
    330 {
    331 	unsigned int len, eol, npos, start, dest;
    332 
    333 	npos = pos;
    334 
    335 	if ((direction == JOIN_NEXT) || (direction == JOIN_NEXT_NW)) {
    336 		npos++;
    337 		  /* see if there is another line following... */
    338 		if (str[npos] == '\0')
    339 			return E_REQUEST_DENIED;
    340 		eol = _formi_find_eol(str, npos);
    341 
    342 		start = npos;
    343 		dest = pos;
    344 		len = eol - npos;
    345 	} else {
    346 		if (pos == 0)
    347 			return E_REQUEST_DENIED;
    348 		eol = _formi_find_eol(str, pos);
    349 		npos--;
    350 		start = pos;
    351 		dest = npos;
    352 		len = eol - pos;
    353 	}
    354 
    355 
    356 	bcopy(&str[start], &str[dest], (unsigned) len);
    357 
    358 	  /* wrap the field if required, if this fails undo the change */
    359 	if ((direction == JOIN_NEXT) || (direction == JOIN_PREV)) {
    360 		if (_formi_wrap_field(field, (unsigned int) pos) != E_OK) {
    361 			bcopy(&str[dest], &str[start], (unsigned) len);
    362 			str[dest] = '\n';
    363 			return E_REQUEST_DENIED;
    364 		}
    365 	}
    366 
    367 	return E_OK;
    368 }
    369 
    370 /*
    371  * skip the blanks in the given string, start at the index start and
    372  * continue forward until either the end of the string or a non-blank
    373  * character is found.  Return the index of either the end of the string or
    374  * the first non-blank character.
    375  */
    376 unsigned
    377 _formi_skip_blanks(char *string, unsigned int start)
    378 {
    379 	unsigned int i;
    380 
    381 	i = start;
    382 
    383 	while ((string[i] != '\0') && isblank(string[i]))
    384 		i++;
    385 
    386 	return i;
    387 }
    388 
    389 /*
    390  * Return the index of the top left most field of the two given fields.
    391  */
    392 static int
    393 _formi_top_left(FORM *form, int a, int b)
    394 {
    395 	  /* lower row numbers always win here.... */
    396 	if (form->fields[a]->form_row < form->fields[b]->form_row)
    397 		return a;
    398 
    399 	if (form->fields[a]->form_row > form->fields[b]->form_row)
    400 		return b;
    401 
    402 	  /* rows must be equal, check columns */
    403 	if (form->fields[a]->form_col < form->fields[b]->form_col)
    404 		return a;
    405 
    406 	if (form->fields[a]->form_col > form->fields[b]->form_col)
    407 		return b;
    408 
    409 	  /* if we get here fields must be in exactly the same place, punt */
    410 	return a;
    411 }
    412 
    413 /*
    414  * Return the index to the field that is the bottom-right-most of the
    415  * two given fields.
    416  */
    417 static int
    418 _formi_bottom_right(FORM *form, int a, int b)
    419 {
    420 	  /* check the rows first, biggest row wins */
    421 	if (form->fields[a]->form_row > form->fields[b]->form_row)
    422 		return a;
    423 	if (form->fields[a]->form_row < form->fields[b]->form_row)
    424 		return b;
    425 
    426 	  /* rows must be equal, check cols, biggest wins */
    427 	if (form->fields[a]->form_col > form->fields[b]->form_col)
    428 		return a;
    429 	if (form->fields[a]->form_col < form->fields[b]->form_col)
    430 		return b;
    431 
    432 	  /* fields in the same place, punt */
    433 	return a;
    434 }
    435 
    436 /*
    437  * Find the next '\n' character in the given string starting at offset
    438  * if there are no newlines found then return the index to the end of the
    439  * string.
    440  */
    441 int
    442 _formi_find_eol(const char *string, unsigned int offset)
    443 {
    444 	char *location;
    445 	int eol;
    446 
    447 	if ((location = index(&string[offset], '\n')) != NULL)
    448 		eol  = location - string;
    449 	else
    450 		eol = strlen(string);
    451 
    452 	if (eol > 0)
    453 		eol--;
    454 
    455 	return eol;
    456 }
    457 
    458 /*
    459  * Find the previous '\n' character in the given string starting at offset
    460  * if there are no newlines found then return 0.
    461  */
    462 int
    463 _formi_find_bol(const char *string, unsigned int offset)
    464 {
    465 	int cnt;
    466 
    467 	cnt = offset;
    468 	while ((cnt > 0) && (string[cnt] != '\n'))
    469 		cnt--;
    470 
    471 	  /* if we moved and found a newline go forward one to point at the
    472 	   * actual start of the line....
    473 	   */
    474 	if ((cnt != offset) && (string[cnt] == '\n'))
    475 		cnt++;
    476 
    477 	return cnt;
    478 }
    479 
    480 /*
    481  * Find the end of the current word in the string str, starting at
    482  * offset - the end includes any trailing whitespace.  If the end of
    483  * the string is found before a new word then just return the offset
    484  * to the end of the string.
    485  */
    486 static int
    487 find_eow(char *str, unsigned int offset)
    488 {
    489 	int start;
    490 
    491 	start = offset;
    492 	  /* first skip any non-whitespace */
    493 	while ((str[start] != '\0') && !isblank(str[start]))
    494 		start++;
    495 
    496 	  /* see if we hit the end of the string */
    497 	if (str[start] == '\0')
    498 		return start;
    499 
    500 	  /* otherwise skip the whitespace.... */
    501 	while ((str[start] != '\0') && isblank(str[start]))
    502 		start++;
    503 
    504 	return start;
    505 }
    506 
    507 /*
    508  * Find the beginning of the current word in the string str, starting
    509  * at offset.
    510  */
    511 static int
    512 find_sow(char *str, unsigned int offset)
    513 {
    514 	int start;
    515 
    516 	start = offset;
    517 
    518 	if (start > 0) {
    519 		if (isblank(str[start]) || isblank(str[start - 1])) {
    520 			if (isblank(str[start - 1]))
    521 				start--;
    522 			  /* skip the whitespace.... */
    523 			while ((start >= 0) && isblank(str[start]))
    524 				start--;
    525 		}
    526 	}
    527 
    528 	  /* see if we hit the start of the string */
    529 	if (start < 0)
    530 		return 0;
    531 
    532 	  /* now skip any non-whitespace */
    533 	while ((start >= 0) && !isblank(str[start]))
    534 		start--;
    535 
    536 	if (start > 0)
    537 		start++; /* last loop has us pointing at a space, adjust */
    538 
    539 	if (start < 0)
    540 		start = 0;
    541 
    542 	return start;
    543 }
    544 
    545 /*
    546  * Scroll the field forward the given number of lines.
    547  */
    548 static void
    549 _formi_scroll_fwd(FIELD *field, unsigned int amt)
    550 {
    551 	  /* check if we have lines to scroll */
    552 	if (field->row_count < (field->start_line + field->rows))
    553 		return;
    554 
    555 	field->start_line += min(amt,
    556 				 field->row_count - field->start_line
    557 				 - field->rows);
    558 }
    559 
    560 /*
    561  * Scroll the field backward the given number of lines.
    562  */
    563 static void
    564 _formi_scroll_back(FIELD *field, unsigned int amt)
    565 {
    566 	if (field->start_line == 0)
    567 		return;
    568 
    569 	field->start_line -= min(field->start_line, amt);
    570 }
    571 
    572 /*
    573  * Scroll the field forward the given number of characters.
    574  */
    575 void
    576 _formi_hscroll_fwd(FIELD *field, int unsigned amt)
    577 {
    578 	int end, scroll_amt;
    579 
    580 	end = _formi_find_eol(field->buffers[0].string,
    581 		       field->start_char + field->cursor_xpos)
    582 		- field->start_char - field->cursor_xpos;
    583 
    584 	scroll_amt = min(amt, end);
    585 	if (scroll_amt < 0)
    586 		scroll_amt = 0;
    587 
    588 	field->start_char += scroll_amt;
    589 }
    590 
    591 /*
    592  * Scroll the field backward the given number of characters.
    593  */
    594 void
    595 _formi_hscroll_back(FIELD *field, unsigned int amt)
    596 {
    597 	field->start_char -= min(field->start_char, amt);
    598 }
    599 
    600 /*
    601  * Find the different pages in the form fields and assign the form
    602  * page_starts array with the information to find them.
    603  */
    604 int
    605 _formi_find_pages(FORM *form)
    606 {
    607 	int i, cur_page = 0;
    608 
    609 	if ((form->page_starts = (_FORMI_PAGE_START *)
    610 	     malloc((form->max_page + 1) * sizeof(_FORMI_PAGE_START))) == NULL)
    611 		return E_SYSTEM_ERROR;
    612 
    613 	  /* initialise the page starts array */
    614 	memset(form->page_starts, 0,
    615 	       (form->max_page + 1) * sizeof(_FORMI_PAGE_START));
    616 
    617 	for (i =0; i < form->field_count; i++) {
    618 		if (form->fields[i]->page_break == 1)
    619 			cur_page++;
    620 		if (form->page_starts[cur_page].in_use == 0) {
    621 			form->page_starts[cur_page].in_use = 1;
    622 			form->page_starts[cur_page].first = i;
    623 			form->page_starts[cur_page].last = i;
    624 			form->page_starts[cur_page].top_left = i;
    625 			form->page_starts[cur_page].bottom_right = i;
    626 		} else {
    627 			form->page_starts[cur_page].last = i;
    628 			form->page_starts[cur_page].top_left =
    629 				_formi_top_left(form,
    630 						form->page_starts[cur_page].top_left,
    631 						i);
    632 			form->page_starts[cur_page].bottom_right =
    633 				_formi_bottom_right(form,
    634 						    form->page_starts[cur_page].bottom_right,
    635 						    i);
    636 		}
    637 	}
    638 
    639 	return E_OK;
    640 }
    641 
    642 /*
    643  * Completely redraw the field of the given form.
    644  */
    645 void
    646 _formi_redraw_field(FORM *form, int field)
    647 {
    648 	unsigned int pre, post, flen, slen, i, row, start, end;
    649 	char *str;
    650 	FIELD *cur;
    651 #ifdef DEBUG
    652 	char buffer[100];
    653 #endif
    654 
    655 	cur = form->fields[field];
    656 	str = cur->buffers[0].string;
    657 	flen = cur->cols;
    658 	slen = 0;
    659 	start = 0;
    660 	end = 0;
    661 
    662 	wmove(form->scrwin, (int) cur->form_row, (int) cur->form_col);
    663 	for (row = 1; row <= cur->row_count; row++) {
    664 		if (str == NULL) {
    665 			start = end = 0;
    666 		} else {
    667 			if ((str[end] == '\0') || (str[end + 1] == '\0')
    668 			    || (row == 1))
    669 				start = end;
    670 			else
    671 				start = end + 1;
    672 		}
    673 
    674 		if (cur->buffers[0].length > 0) {
    675 			end = _formi_find_eol(str, start);
    676 			slen = end - start + 1;
    677 		} else
    678 			slen = 0;
    679 
    680 		if ((cur->opts & O_STATIC) == O_STATIC) {
    681 			switch (cur->justification) {
    682 			case JUSTIFY_RIGHT:
    683 				post = 0;
    684 				if (flen < slen)
    685 					pre = 0;
    686 				else
    687 					pre = flen - slen;
    688 				break;
    689 
    690 			case JUSTIFY_CENTER:
    691 				if (flen < slen) {
    692 					pre = 0;
    693 					post = 0;
    694 				} else {
    695 					pre = flen - slen;
    696 					post = pre = pre / 2;
    697 					  /* get padding right if
    698                                              centring is not even */
    699 					if ((post + pre + slen) < flen)
    700 						post++;
    701 				}
    702 				break;
    703 
    704 			case NO_JUSTIFICATION:
    705 			case JUSTIFY_LEFT:
    706 			default:
    707 				pre = 0;
    708 				if (flen <= slen)
    709 					post = 0;
    710 				else {
    711 					post = flen - slen;
    712 					if (post > flen)
    713 						post = flen;
    714 				}
    715 				break;
    716 			}
    717 		} else {
    718 			  /* dynamic fields are not justified */
    719 			pre = 0;
    720 			if (flen <= slen)
    721 				post = 0;
    722 			else {
    723 				post = flen - slen;
    724 				if (post > flen)
    725 					post = flen;
    726 			}
    727 
    728 			  /* but they do scroll.... */
    729 
    730 			if (pre > cur->start_char - start)
    731 				pre = pre - cur->start_char + start;
    732 			else
    733 				pre = 0;
    734 
    735 			if (slen > cur->start_char) {
    736 				slen -= cur->start_char;
    737 				post += cur->start_char;
    738 				if (post > flen)
    739 					post = flen;
    740 			} else {
    741 				slen = 0;
    742 				post = flen - pre;
    743 			}
    744 		}
    745 
    746 		if (form->cur_field == field)
    747 			wattrset(form->scrwin, cur->fore);
    748 		else
    749 			wattrset(form->scrwin, cur->back);
    750 
    751 #ifdef DEBUG
    752 		if (_formi_create_dbg_file() == E_OK) {
    753 			fprintf(dbg,
    754   "redraw_field: start=%d, pre=%d, slen=%d, flen=%d, post=%d, start_char=%d\n",
    755 				start, pre, slen, flen, post, cur->start_char);
    756 			if (str != NULL) {
    757 				strncpy(buffer, &str[cur->start_char], flen);
    758 			} else {
    759 				strcpy(buffer, "(null)");
    760 			}
    761 			buffer[flen] = '\0';
    762 			fprintf(dbg, "redraw_field: %s\n", buffer);
    763 		}
    764 #endif
    765 
    766 		for (i = start + cur->start_char; i < pre; i++)
    767 			waddch(form->scrwin, cur->pad);
    768 
    769 #ifdef DEBUG
    770 		fprintf(dbg, "redraw_field: will add %d chars\n",
    771 			min(slen, flen));
    772 #endif
    773 		for (i = 0; i < min(slen, flen); i++)
    774 		{
    775 #ifdef DEBUG
    776 			fprintf(dbg, "adding char str[%d]=%c\n",
    777 				i + cur->start_char, str[i + cur->start_char]);
    778 #endif
    779 			if (((cur->opts & O_PUBLIC) != O_PUBLIC)) {
    780 				waddch(form->scrwin, cur->pad);
    781 			} else if ((cur->opts & O_VISIBLE) == O_VISIBLE) {
    782 				waddch(form->scrwin, str[i + cur->start_char]);
    783 			} else {
    784 				waddch(form->scrwin, ' ');
    785 			}
    786 		}
    787 
    788 		for (i = 0; i < post; i++)
    789 			waddch(form->scrwin, cur->pad);
    790 	}
    791 
    792 	return;
    793 }
    794 
    795 /*
    796  * Display the fields attached to the form that are on the current page
    797  * on the screen.
    798  *
    799  */
    800 int
    801 _formi_draw_page(FORM *form)
    802 {
    803 	int i;
    804 
    805 	if (form->page_starts[form->page].in_use == 0)
    806 		return E_BAD_ARGUMENT;
    807 
    808 	wclear(form->scrwin);
    809 
    810 	for (i = form->page_starts[form->page].first;
    811 	     i <= form->page_starts[form->page].last; i++)
    812 		_formi_redraw_field(form, i);
    813 
    814 	return E_OK;
    815 }
    816 
    817 /*
    818  * Add the character c at the position pos in buffer 0 of the given field
    819  */
    820 int
    821 _formi_add_char(FIELD *field, unsigned int pos, char c)
    822 {
    823 	char *new;
    824 	unsigned int new_size;
    825 	int status;
    826 
    827 	  /*
    828 	   * If buffer has not had a string before, set it to a blank
    829 	   * string.  Everything should flow from there....
    830 	   */
    831 	if (field->buffers[0].string == NULL) {
    832 		set_field_buffer(field, 0, "");
    833 	}
    834 
    835 	if (_formi_validate_char(field, c) != E_OK) {
    836 #ifdef DEBUG
    837 		fprintf(dbg, "add_char: char %c failed char validation\n", c);
    838 #endif
    839 		return E_INVALID_FIELD;
    840 	}
    841 
    842 #ifdef DEBUG
    843 	fprintf(dbg, "add_char: pos=%d, char=%c\n", pos, c);
    844 	fprintf(dbg,
    845 	   "add_char enter: xpos=%d, start=%d, length=%d(%d), allocated=%d\n",
    846 		field->cursor_xpos, field->start_char,
    847 		field->buffers[0].length, strlen(field->buffers[0].string),
    848 		field->buffers[0].allocated);
    849 	fprintf(dbg, "add_char enter: %s\n", field->buffers[0].string);
    850 	fprintf(dbg, "add_char enter: buf0_status=%d\n", field->buf0_status);
    851 #endif
    852 	if (((field->opts & O_BLANK) == O_BLANK) &&
    853 	    (field->buf0_status == FALSE) &&
    854 	    ((field->cursor_xpos + field->start_char) == 0)) {
    855 		field->buffers[0].length = 0;
    856 		field->buffers[0].string[0] = '\0';
    857 		pos = 0;
    858 		field->start_char = 0;
    859 		field->start_line = 0;
    860 		field->row_count = 1;
    861 		field->cursor_xpos = 0;
    862 		field->cursor_ypos = 0;
    863 	}
    864 
    865 
    866 	if ((field->overlay == 0)
    867 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
    868 		  /* first check if the field can have more chars...*/
    869 		if ((((field->opts & O_STATIC) == O_STATIC) &&
    870 		     (field->buffers[0].length >= field->cols)) ||
    871 		    (((field->opts & O_STATIC) != O_STATIC) &&
    872 /*XXXXX this is wrong - should check max row or col */		     ((field->max > 0) &&
    873 		      (field->buffers[0].length >= field->max))))
    874 			return E_REQUEST_DENIED;
    875 
    876 		if (field->buffers[0].length + 1
    877 		    >= field->buffers[0].allocated) {
    878 			new_size = field->buffers[0].allocated + 64
    879 				- (field->buffers[0].allocated % 64);
    880 			if ((new = (char *) realloc(field->buffers[0].string,
    881 						    new_size )) == NULL)
    882 				return E_SYSTEM_ERROR;
    883 			field->buffers[0].allocated = new_size;
    884 			field->buffers[0].string = new;
    885 		}
    886 	}
    887 
    888 	if ((field->overlay == 0) && (field->buffers[0].length > pos)) {
    889 		bcopy(&field->buffers[0].string[pos],
    890 		      &field->buffers[0].string[pos + 1],
    891 		      field->buffers[0].length - pos + 1);
    892 	}
    893 
    894 	field->buffers[0].string[pos] = c;
    895 	if (pos >= field->buffers[0].length) {
    896 		  /* make sure the string is terminated if we are at the
    897 		   * end of the string, the terminator would be missing
    898 		   * if we are are at the end of the field.
    899 		   */
    900 		field->buffers[0].string[pos + 1] = '\0';
    901 	}
    902 
    903 	  /* only increment the length if we are inserting characters
    904 	   * OR if we are at the end of the field in overlay mode.
    905 	   */
    906 	if ((field->overlay == 0)
    907 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length)))
    908 			field->buffers[0].length++;
    909 
    910 	  /* wrap the field, if needed */
    911 	status = _formi_wrap_field(field, pos);
    912 	if (status != E_OK) {
    913 		  /* wrap failed for some reason, back out the char insert */
    914 		bcopy(&field->buffers[0].string[pos + 1],
    915 		      &field->buffers[0].string[pos],
    916 		      field->buffers[0].length - pos);
    917 		field->buffers[0].length--;
    918 	} else {
    919 		field->buf0_status = TRUE;
    920 
    921 		if ((field->cursor_xpos < (field->cols - 1)) ||
    922 		    ((field->opts & O_STATIC) != O_STATIC))
    923 			field->cursor_xpos++;
    924 
    925 		if (field->cursor_xpos > field->cols) {
    926 			field->start_char++;
    927 			field->cursor_xpos = field->cols;
    928 		}
    929 	}
    930 
    931 #ifdef DEBUG
    932 	fprintf(dbg,
    933 	    "add_char exit: xpos=%d, start=%d, length=%d(%d), allocated=%d\n",
    934 		field->cursor_xpos, field->start_char,
    935 		field->buffers[0].length, strlen(field->buffers[0].string),
    936 		field->buffers[0].allocated);
    937 	fprintf(dbg,"add_char exit: %s\n", field->buffers[0].string);
    938 	fprintf(dbg, "add_char exit: buf0_status=%d\n", field->buf0_status);
    939 	fprintf(dbg, "add_char exit: status = %s\n",
    940 		(status == E_OK)? "OK" : "FAILED");
    941 #endif
    942 	return status;
    943 }
    944 
    945 /*
    946  * Manipulate the text in a field, this takes the given form and performs
    947  * the passed driver command on the current text field.  Returns 1 if the
    948  * text field was modified.
    949  */
    950 int
    951 _formi_manipulate_field(FORM *form, int c)
    952 {
    953 	FIELD *cur;
    954 	char *str;
    955 	unsigned int i, start, end, pos;
    956 
    957 	cur = form->fields[form->cur_field];
    958 
    959 #ifdef DEBUG
    960 	fprintf(dbg,
    961 		"entry: xpos=%d, start_char=%d, length=%d, allocated=%d\n",
    962 		cur->cursor_xpos, cur->start_char, cur->buffers[0].length,
    963 		cur->buffers[0].allocated);
    964 	fprintf(dbg, "entry: string=");
    965 	if (cur->buffers[0].string == NULL)
    966 		fprintf(dbg, "(null)\n");
    967 	else
    968 		fprintf(dbg, "\"%s\"\n", cur->buffers[0].string);
    969 #endif
    970 
    971 	  /* Cannot manipulate a null string! */
    972 	if (cur->buffers[0].string == NULL)
    973 		return E_REQUEST_DENIED;
    974 
    975 	switch (c) {
    976 	case REQ_NEXT_CHAR:
    977 		  /* for a dynamic field allow an offset of one more
    978 		   * char so we can insert chars after end of string.
    979 		   * Static fields cannot do this so deny request if
    980 		   * cursor is at the end of the field.
    981 		   */
    982 		if (((cur->opts & O_STATIC) == O_STATIC) &&
    983 		    (cur->cursor_xpos == cur->cols - 1))
    984 			return E_REQUEST_DENIED;
    985 
    986 		if ((cur->cursor_xpos + cur->start_char + 1)
    987 		    > cur->buffers[0].length)
    988 			return E_REQUEST_DENIED;
    989 
    990 		cur->cursor_xpos++;
    991 		if (cur->cursor_xpos >= cur->cols - 1) {
    992 			cur->cursor_xpos = cur->cols - 1;
    993 			if ((cur->opts & O_STATIC) != O_STATIC)
    994 				cur->start_char++;
    995 		}
    996 		break;
    997 
    998 	case REQ_PREV_CHAR:
    999 		if (cur->cursor_xpos == 0) {
   1000 			if (cur->start_char > 0)
   1001 				cur->start_char--;
   1002 			else
   1003 				return E_REQUEST_DENIED;
   1004 		} else
   1005 			cur->cursor_xpos--;
   1006 		break;
   1007 
   1008 	case REQ_NEXT_LINE:
   1009 		cur->cursor_ypos++;
   1010 		if (cur->cursor_ypos > cur->rows) {
   1011 			if ((cur->opts & O_STATIC) == O_STATIC) {
   1012 				if (cur->start_line + cur->cursor_ypos
   1013 				    > cur->drows) {
   1014 					cur->cursor_ypos--;
   1015 					return E_REQUEST_DENIED;
   1016 				}
   1017 			} else {
   1018 				if (cur->start_line + cur->cursor_ypos
   1019 				    > cur->nrows + cur->rows) {
   1020 					cur->cursor_ypos--;
   1021 					return E_REQUEST_DENIED;
   1022 				}
   1023 			}
   1024 			cur->start_line++;
   1025 		}
   1026 		break;
   1027 
   1028 	case REQ_PREV_LINE:
   1029 		if (cur->cursor_ypos == 0) {
   1030 			if (cur->start_line == 0)
   1031 				return E_REQUEST_DENIED;
   1032 			cur->start_line--;
   1033 		} else
   1034 			cur->cursor_ypos--;
   1035 		break;
   1036 
   1037 	case REQ_NEXT_WORD:
   1038 		start = cur->start_char + cur->cursor_xpos;
   1039 		str = cur->buffers[0].string;
   1040 
   1041 		start = find_eow(str, start);
   1042 
   1043 		  /* check if we hit the end */
   1044 		if (str[start] == '\0')
   1045 			return E_REQUEST_DENIED;
   1046 
   1047 		  /* otherwise we must have found the start of a word...*/
   1048 		if (start - cur->start_char < cur->cols) {
   1049 			cur->cursor_xpos = start;
   1050 		} else {
   1051 			cur->start_char = start;
   1052 			cur->cursor_xpos = 0;
   1053 		}
   1054 		break;
   1055 
   1056 	case REQ_PREV_WORD:
   1057 		start = cur->start_char + cur->cursor_xpos;
   1058 		if (cur->start_char > 0)
   1059 			start--;
   1060 
   1061 		if (start == 0)
   1062 			return E_REQUEST_DENIED;
   1063 
   1064 		str = cur->buffers[0].string;
   1065 
   1066 		start = find_sow(str, start);
   1067 
   1068 		if (start - cur->start_char > 0) {
   1069 			cur->cursor_xpos = start;
   1070 		} else {
   1071 			cur->start_char = start;
   1072 			cur->cursor_xpos = 0;
   1073 		}
   1074 		break;
   1075 
   1076 	case REQ_BEG_FIELD:
   1077 		cur->start_char = 0;
   1078 		cur->start_line = 0;
   1079 		cur->cursor_xpos = 0;
   1080 		cur->cursor_ypos = 0;
   1081 		break;
   1082 
   1083 	case REQ_BEG_LINE:
   1084 		start = cur->start_char + cur->cursor_xpos;
   1085 		if (cur->buffers[0].string[start] == '\n') {
   1086 			if (start > 0)
   1087 				start--;
   1088 			else
   1089 				return E_REQUEST_DENIED;
   1090 		}
   1091 
   1092 		while ((start > 0)
   1093 		       && (cur->buffers[0].string[start] != '\n'))
   1094 			start--;
   1095 
   1096 		if (start > 0)
   1097 			start++;
   1098 
   1099 		cur->start_char = start;
   1100 		cur->cursor_xpos = 0;
   1101 		break;
   1102 
   1103 	case REQ_END_FIELD:
   1104 		if (cur->row_count > cur->rows) {
   1105 			cur->start_line = cur->row_count - cur->rows;
   1106 			cur->cursor_ypos = cur->rows - 1;
   1107 		} else {
   1108 			cur->start_line = 0;
   1109 			cur->cursor_ypos = cur->row_count - 1;
   1110 		}
   1111 
   1112 		if ((str = rindex(cur->buffers[0].string, '\n')) == NULL) {
   1113 			cur->start_char = 0;
   1114 
   1115 		} else {
   1116 			cur->start_char = (str - cur->buffers[0].string) + 1;
   1117 		}
   1118 
   1119 		cur->cursor_xpos = 0;
   1120 		  /* we fall through here deliberately, we are on the
   1121 		   * correct row, now we need to get to the end of the
   1122 		   * line.
   1123 		   */
   1124 		  /* FALLTHRU */
   1125 
   1126 	case REQ_END_LINE:
   1127 		start = cur->start_char + cur->cursor_xpos;
   1128 		end = _formi_find_eol(cur->buffers[0].string, start);
   1129 		start = _formi_find_bol(cur->buffers[0].string, start);
   1130 
   1131 		if (end - start > cur->cols - 1) {
   1132 			cur->cursor_xpos = cur->cols - 1;
   1133 			cur->start_char = end - cur->cols;
   1134 			if ((cur->opts & O_STATIC) != O_STATIC)
   1135 				cur->start_char++;
   1136 		} else {
   1137 			cur->cursor_xpos = end - start + 1;
   1138 			if (((cur->opts & O_STATIC) == O_STATIC) &&
   1139 			    ((end - start) == (cur->cols - 1)))
   1140 				cur->cursor_xpos--;
   1141 
   1142 			cur->start_char = start;
   1143 		}
   1144 		break;
   1145 
   1146 	case REQ_LEFT_CHAR:
   1147 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0))
   1148 			return E_REQUEST_DENIED;
   1149 
   1150 		if (cur->cursor_xpos == 0) {
   1151 			cur->start_char--;
   1152 			if (cur->buffers[0].string[cur->start_char] == '\n') {
   1153 				if ((cur->cursor_ypos == 0) &&
   1154 				    (cur->start_line == 0))
   1155 				{
   1156 					cur->start_char++;
   1157 					return E_REQUEST_DENIED;
   1158 				}
   1159 
   1160 				if (cur->cursor_ypos == 0)
   1161 					cur->start_line--;
   1162 				else
   1163 					cur->cursor_ypos--;
   1164 
   1165 				end = _formi_find_eol(cur->buffers[0].string,
   1166 					       cur->start_char);
   1167 				start = _formi_find_bol(cur->buffers[0].string,
   1168 						 cur->start_char);
   1169 				if (end - start >= cur->cols) {
   1170 					cur->cursor_xpos = cur->cols - 1;
   1171 					cur->start_char = end - cur->cols;
   1172 				} else {
   1173 					cur->cursor_xpos = end - start;
   1174 					cur->start_char = start;
   1175 				}
   1176 			}
   1177 		} else
   1178 			cur->cursor_xpos--;
   1179 		break;
   1180 
   1181 	case REQ_RIGHT_CHAR:
   1182 		pos = cur->start_char + cur->cursor_xpos;
   1183 		if (cur->buffers[0].string[pos] == '\0')
   1184 			return E_REQUEST_DENIED;
   1185 
   1186 #ifdef DEBUG
   1187 		fprintf(dbg, "req_right_char enter: start=%d, xpos=%d, c=%c\n",
   1188 			cur->start_char, cur->cursor_xpos,
   1189 			cur->buffers[0].string[pos]);
   1190 #endif
   1191 
   1192 		if (cur->buffers[0].string[pos] == '\n') {
   1193 			start = pos + 1;
   1194 			if (cur->buffers[0].string[start] == 0)
   1195 				return E_REQUEST_DENIED;
   1196 			end = _formi_find_eol(cur->buffers[0].string, start);
   1197 			if (end - start > cur->cols) {
   1198 				cur->cursor_xpos = cur->cols - 1;
   1199 				cur->start_char = end - cur->cols - 1;
   1200 			} else {
   1201 				cur->cursor_xpos = end - start;
   1202 				cur->start_char = start;
   1203 			}
   1204 		} else {
   1205 			if (cur->cursor_xpos == cur->cols - 1)
   1206 				cur->start_char++;
   1207 			else
   1208 				cur->cursor_xpos++;
   1209 		}
   1210 #ifdef DEBUG
   1211 		fprintf(dbg, "req_right_char exit: start=%d, xpos=%d, c=%c\n",
   1212 			cur->start_char, cur->cursor_xpos,
   1213 			cur->buffers[0].string[cur->start_char +
   1214 					      cur->cursor_xpos]);
   1215 #endif
   1216 		break;
   1217 
   1218 	case REQ_UP_CHAR:
   1219 		if (cur->cursor_ypos == 0) {
   1220 			if (cur->start_line == 0)
   1221 				return E_REQUEST_DENIED;
   1222 
   1223 			cur->start_line--;
   1224 		} else
   1225 			cur->cursor_ypos--;
   1226 
   1227 		start = find_cur_line(cur);
   1228 		end = _formi_find_eol(cur->buffers[0].string, start);
   1229 		cur->start_char = start;
   1230 		if (cur->cursor_xpos > end - start)
   1231 			cur->cursor_xpos = end - start;
   1232 		break;
   1233 
   1234 	case REQ_DOWN_CHAR:
   1235 		if (cur->cursor_ypos == cur->rows - 1) {
   1236 			if (cur->start_line + cur->rows == cur->row_count)
   1237 				return E_REQUEST_DENIED;
   1238 			cur->start_line++;
   1239 		} else
   1240 			cur->cursor_ypos++;
   1241 
   1242 		start = find_cur_line(cur);
   1243 		end = _formi_find_eol(cur->buffers[0].string, start);
   1244 		cur->start_char = start;
   1245 		if (cur->cursor_xpos > end - start)
   1246 			cur->cursor_xpos = end - start;
   1247 		break;
   1248 
   1249 	case REQ_NEW_LINE:
   1250 		if (_formi_add_char(cur, cur->start_char + cur->cursor_xpos,
   1251 				    '\n') == E_OK)
   1252 			cur->row_count++;
   1253 		break;
   1254 
   1255 	case REQ_INS_CHAR:
   1256 		_formi_add_char(cur, cur->start_char + cur->cursor_xpos,
   1257 				cur->pad);
   1258 		break;
   1259 
   1260 	case REQ_INS_LINE:
   1261 		start = _formi_find_bol(cur->buffers[0].string, cur->start_char);
   1262 		if (_formi_add_char(cur, start, '\n') == E_OK)
   1263 			cur->row_count++;
   1264 		break;
   1265 
   1266 	case REQ_DEL_CHAR:
   1267 		if (cur->buffers[0].string[cur->start_char + cur->cursor_xpos]
   1268 		    == '\0')
   1269 			return E_REQUEST_DENIED;
   1270 
   1271 		start = cur->start_char + cur->cursor_xpos;
   1272 		end = cur->buffers[0].length;
   1273 		if (cur->buffers[0].string[start] == '\n') {
   1274 			if (cur->row_count > 1) {
   1275 				cur->row_count--;
   1276 				_formi_join_line(cur, cur->buffers[0].string,
   1277 						 start, JOIN_NEXT);
   1278 			} else
   1279 				cur->buffers[0].string[start] = '\0';
   1280 		} else {
   1281 			bcopy(&cur->buffers[0].string[start + 1],
   1282 			      &cur->buffers[0].string[start],
   1283 			      (unsigned) end - start + 1);
   1284 		}
   1285 
   1286 		cur->buffers[0].length--;
   1287 		break;
   1288 
   1289 	case REQ_DEL_PREV:
   1290 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0))
   1291 			   return E_REQUEST_DENIED;
   1292 
   1293 		start = cur->cursor_xpos + cur->start_char;
   1294 		end = cur->buffers[0].length;
   1295 
   1296 		if (cur->buffers[0].string[cur->start_char + cur->cursor_xpos] == '\n') {
   1297 			_formi_join_line(cur, cur->buffers[0].string,
   1298 					 cur->start_char + cur->cursor_xpos,
   1299 					 JOIN_PREV);
   1300 			cur->row_count--;
   1301 		} else {
   1302 			bcopy(&cur->buffers[0].string[start],
   1303 			      &cur->buffers[0].string[start - 1],
   1304 			      (unsigned) end - start + 1);
   1305 		}
   1306 
   1307 		cur->buffers[0].length--;
   1308 		if ((cur->cursor_xpos == 0) && (cur->start_char > 0))
   1309 			cur->start_char--;
   1310 		else if ((cur->cursor_xpos == cur->cols - 1)
   1311 			 && (cur->start_char > 0))
   1312 			cur->start_char--;
   1313 		else if (cur->cursor_xpos > 0)
   1314 			cur->cursor_xpos--;
   1315 
   1316 		break;
   1317 
   1318 	case REQ_DEL_LINE:
   1319 		start = cur->start_char + cur->cursor_xpos;
   1320 		end = _formi_find_eol(cur->buffers[0].string, start);
   1321 		start = _formi_find_bol(cur->buffers[0].string, start);
   1322 		bcopy(&cur->buffers[0].string[end + 1],
   1323 		      &cur->buffers[0].string[start],
   1324 		      (unsigned) cur->buffers[0].length - end + 1);
   1325 		if (cur->row_count > 1)
   1326 			cur->row_count--;
   1327 		break;
   1328 
   1329 	case REQ_DEL_WORD:
   1330 		start = cur->start_char + cur->cursor_xpos;
   1331 		end = find_eow(cur->buffers[0].string, start);
   1332 		start = find_sow(cur->buffers[0].string, start);
   1333 		bcopy(&cur->buffers[0].string[end + 1],
   1334 		      &cur->buffers[0].string[start],
   1335 		      (unsigned) cur->buffers[0].length - end + 1);
   1336 		cur->buffers[0].length -= end - start;
   1337 		break;
   1338 
   1339 	case REQ_CLR_EOL:
   1340 		  /*XXXX this right or should we just toast the chars? */
   1341 		start = cur->start_char + cur->cursor_xpos;
   1342 		end = _formi_find_eol(cur->buffers[0].string, start);
   1343 		for (i = start; i < end; i++)
   1344 			cur->buffers[0].string[i] = cur->pad;
   1345 		break;
   1346 
   1347 	case REQ_CLR_EOF:
   1348 		for (i = cur->start_char + cur->cursor_xpos;
   1349 		     i < cur->buffers[0].length; i++)
   1350 			cur->buffers[0].string[i] = cur->pad;
   1351 		break;
   1352 
   1353 	case REQ_CLR_FIELD:
   1354 		for (i = 0; i < cur->buffers[0].length; i++)
   1355 			cur->buffers[0].string[i] = cur->pad;
   1356 		break;
   1357 
   1358 	case REQ_OVL_MODE:
   1359 		cur->overlay = 1;
   1360 		break;
   1361 
   1362 	case REQ_INS_MODE:
   1363 		cur->overlay = 0;
   1364 		break;
   1365 
   1366 	case REQ_SCR_FLINE:
   1367 		_formi_scroll_fwd(cur, 1);
   1368 		break;
   1369 
   1370 	case REQ_SCR_BLINE:
   1371 		_formi_scroll_back(cur, 1);
   1372 		break;
   1373 
   1374 	case REQ_SCR_FPAGE:
   1375 		_formi_scroll_fwd(cur, cur->rows);
   1376 		break;
   1377 
   1378 	case REQ_SCR_BPAGE:
   1379 		_formi_scroll_back(cur, cur->rows);
   1380 		break;
   1381 
   1382 	case REQ_SCR_FHPAGE:
   1383 		_formi_scroll_fwd(cur, cur->rows / 2);
   1384 		break;
   1385 
   1386 	case REQ_SCR_BHPAGE:
   1387 		_formi_scroll_back(cur, cur->rows / 2);
   1388 		break;
   1389 
   1390 	case REQ_SCR_FCHAR:
   1391 		_formi_hscroll_fwd(cur, 1);
   1392 		break;
   1393 
   1394 	case REQ_SCR_BCHAR:
   1395 		_formi_hscroll_back(cur, 1);
   1396 		break;
   1397 
   1398 	case REQ_SCR_HFLINE:
   1399 		_formi_hscroll_fwd(cur, cur->cols);
   1400 		break;
   1401 
   1402 	case REQ_SCR_HBLINE:
   1403 		_formi_hscroll_back(cur, cur->cols);
   1404 		break;
   1405 
   1406 	case REQ_SCR_HFHALF:
   1407 		_formi_hscroll_fwd(cur, cur->cols / 2);
   1408 		break;
   1409 
   1410 	case REQ_SCR_HBHALF:
   1411 		_formi_hscroll_back(cur, cur->cols / 2);
   1412 		break;
   1413 
   1414 	default:
   1415 		return 0;
   1416 	}
   1417 
   1418 #ifdef DEBUG
   1419 	fprintf(dbg, "exit: xpos=%d, start_char=%d, length=%d, allocated=%d\n",
   1420 		cur->cursor_xpos, cur->start_char, cur->buffers[0].length,
   1421 		cur->buffers[0].allocated);
   1422 	fprintf(dbg, "exit: string=\"%s\"\n", cur->buffers[0].string);
   1423 #endif
   1424 	return 1;
   1425 }
   1426 
   1427 /*
   1428  * Validate the give character by passing it to any type character
   1429  * checking routines, if they exist.
   1430  */
   1431 int
   1432 _formi_validate_char(FIELD *field, char c)
   1433 {
   1434 	int ret_val;
   1435 
   1436 	if (field->type == NULL)
   1437 		return E_OK;
   1438 
   1439 	ret_val = E_INVALID_FIELD;
   1440 	_formi_do_char_validation(field, field->type, c, &ret_val);
   1441 
   1442 	return ret_val;
   1443 }
   1444 
   1445 
   1446 /*
   1447  * Perform the validation of the character, invoke all field_type validation
   1448  * routines.  If the field is ok then update ret_val to E_OK otherwise
   1449  * ret_val is not changed.
   1450  */
   1451 static void
   1452 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val)
   1453 {
   1454 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
   1455 		_formi_do_char_validation(field, type->link->next, c, ret_val);
   1456 		_formi_do_char_validation(field, type->link->prev, c, ret_val);
   1457 	} else {
   1458 		if (type->char_check == NULL)
   1459 			*ret_val = E_OK;
   1460 		else {
   1461 			if (type->char_check((int)(unsigned char) c,
   1462 					     field->args) == TRUE)
   1463 				*ret_val = E_OK;
   1464 		}
   1465 	}
   1466 }
   1467 
   1468 /*
   1469  * Validate the current field.  If the field validation returns success then
   1470  * return E_OK otherwise return E_INVALID_FIELD.
   1471  *
   1472  */
   1473 int
   1474 _formi_validate_field(FORM *form)
   1475 {
   1476 	FIELD *cur;
   1477 	char *bp;
   1478 	int ret_val, count;
   1479 
   1480 
   1481 	if ((form == NULL) || (form->fields == NULL) ||
   1482 	    (form->fields[0] == NULL))
   1483 		return E_INVALID_FIELD;
   1484 
   1485 	cur = form->fields[form->cur_field];
   1486 
   1487 	bp = cur->buffers[0].string;
   1488 	count = _formi_skip_blanks(bp, 0);
   1489 
   1490 	  /* check if we have a null field, depending on the nullok flag
   1491 	   * this may be acceptable or not....
   1492 	   */
   1493 	if (cur->buffers[0].string[count] == '\0') {
   1494 		if ((cur->opts & O_NULLOK) == O_NULLOK)
   1495 			return E_OK;
   1496 		else
   1497 			return E_INVALID_FIELD;
   1498 	}
   1499 
   1500 	  /* check if an unmodified field is ok */
   1501 	if (cur->buf0_status == 0) {
   1502 		if ((cur->opts & O_PASSOK) == O_PASSOK)
   1503 			return E_OK;
   1504 		else
   1505 			return E_INVALID_FIELD;
   1506 	}
   1507 
   1508 	  /* if there is no type then just accept the field */
   1509 	if (cur->type == NULL)
   1510 		return E_OK;
   1511 
   1512 	ret_val = E_INVALID_FIELD;
   1513 	_formi_do_validation(cur, cur->type, &ret_val);
   1514 
   1515 	return ret_val;
   1516 }
   1517 
   1518 /*
   1519  * Perform the validation of the field, invoke all field_type validation
   1520  * routines.  If the field is ok then update ret_val to E_OK otherwise
   1521  * ret_val is not changed.
   1522  */
   1523 static void
   1524 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val)
   1525 {
   1526 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
   1527 		_formi_do_validation(field, type->link->next, ret_val);
   1528 		_formi_do_validation(field, type->link->prev, ret_val);
   1529 	} else {
   1530 		if (type->field_check == NULL)
   1531 			*ret_val = E_OK;
   1532 		else {
   1533 			if (type->field_check(field, field_buffer(field, 0))
   1534 			    == TRUE)
   1535 				*ret_val = E_OK;
   1536 		}
   1537 	}
   1538 }
   1539 
   1540 /*
   1541  * Select the next/previous choice for the field, the driver command
   1542  * selecting the direction will be passed in c.  Return 1 if a choice
   1543  * selection succeeded, 0 otherwise.
   1544  */
   1545 int
   1546 _formi_field_choice(FORM *form, int c)
   1547 {
   1548 	FIELDTYPE *type;
   1549 	FIELD *field;
   1550 
   1551 	if ((form == NULL) || (form->fields == NULL) ||
   1552 	    (form->fields[0] == NULL) ||
   1553 	    (form->fields[form->cur_field]->type == NULL))
   1554 		return 0;
   1555 
   1556 	field = form->fields[form->cur_field];
   1557 	type = field->type;
   1558 
   1559 	switch (c) {
   1560 	case REQ_NEXT_CHOICE:
   1561 		if (type->next_choice == NULL)
   1562 			return 0;
   1563 		else
   1564 			return type->next_choice(field,
   1565 						 field_buffer(field, 0));
   1566 
   1567 	case REQ_PREV_CHOICE:
   1568 		if (type->prev_choice == NULL)
   1569 			return 0;
   1570 		else
   1571 			return type->prev_choice(field,
   1572 						 field_buffer(field, 0));
   1573 
   1574 	default: /* should never happen! */
   1575 		return 0;
   1576 	}
   1577 }
   1578 
   1579 /*
   1580  * Update the fields if they have changed.  The parameter old has the
   1581  * previous current field as the current field may have been updated by
   1582  * the driver.  Return 1 if the form page needs updating.
   1583  *
   1584  */
   1585 int
   1586 _formi_update_field(FORM *form, int old_field)
   1587 {
   1588 	int cur, i;
   1589 
   1590 	cur = form->cur_field;
   1591 
   1592 	if (old_field != cur) {
   1593 		if (!((cur >= form->page_starts[form->page].first) &&
   1594 		      (cur <= form->page_starts[form->page].last))) {
   1595 			  /* not on same page any more */
   1596 			for (i = 0; i < form->max_page; i++) {
   1597 				if ((form->page_starts[i].in_use == 1) &&
   1598 				    (form->page_starts[i].first <= cur) &&
   1599 				    (form->page_starts[i].last >= cur)) {
   1600 					form->page = i;
   1601 					return 1;
   1602 				}
   1603 			}
   1604 		}
   1605 	}
   1606 
   1607 	_formi_redraw_field(form, old_field);
   1608 	_formi_redraw_field(form, form->cur_field);
   1609 	return 0;
   1610 }
   1611 
   1612 /*
   1613  * Compare function for the field sorting
   1614  *
   1615  */
   1616 static int
   1617 field_sort_compare(const void *one, const void *two)
   1618 {
   1619 	const FIELD *a, *b;
   1620 	int tl;
   1621 
   1622 	  /* LINTED const castaway; we don't modify these! */
   1623 	a = (const FIELD *) *((const FIELD **) one);
   1624 	b = (const FIELD *) *((const FIELD **) two);
   1625 
   1626 	if (a == NULL)
   1627 		return 1;
   1628 
   1629 	if (b == NULL)
   1630 		return -1;
   1631 
   1632 	  /*
   1633 	   * First check the page, we want the fields sorted by page.
   1634 	   *
   1635 	   */
   1636 	if (a->page != b->page)
   1637 		return ((a->page > b->page)? 1 : -1);
   1638 
   1639 	tl = _formi_top_left(a->parent, a->index, b->index);
   1640 
   1641 	  /*
   1642 	   * sort fields left to right, top to bottom so the top left is
   1643 	   * the less than value....
   1644 	   */
   1645 	return ((tl == a->index)? -1 : 1);
   1646 }
   1647 
   1648 /*
   1649  * Sort the fields in a form ready for driver traversal.
   1650  */
   1651 void
   1652 _formi_sort_fields(FORM *form)
   1653 {
   1654 	FIELD **sort_area;
   1655 	int i;
   1656 
   1657 	CIRCLEQ_INIT(&form->sorted_fields);
   1658 
   1659 	if ((sort_area = (FIELD **) malloc(sizeof(FIELD *) * form->field_count))
   1660 	    == NULL)
   1661 		return;
   1662 
   1663 	bcopy(form->fields, sort_area, sizeof(FIELD *) * form->field_count);
   1664 	qsort(sort_area, (unsigned) form->field_count, sizeof(FIELD *),
   1665 	      field_sort_compare);
   1666 
   1667 	for (i = 0; i < form->field_count; i++)
   1668 		CIRCLEQ_INSERT_TAIL(&form->sorted_fields, sort_area[i], glue);
   1669 
   1670 	free(sort_area);
   1671 }
   1672 
   1673 /*
   1674  * Set the neighbours for all the fields in the given form.
   1675  */
   1676 void
   1677 _formi_stitch_fields(FORM *form)
   1678 {
   1679 	int above_row, below_row, end_above, end_below, cur_row, real_end;
   1680 	FIELD *cur, *above, *below;
   1681 
   1682 	  /*
   1683 	   * check if the sorted fields circle queue is empty, just
   1684 	   * return if it is.
   1685 	   */
   1686 	if (CIRCLEQ_EMPTY(&form->sorted_fields))
   1687 		return;
   1688 
   1689 	  /* initially nothing is above..... */
   1690 	above_row = -1;
   1691 	end_above = TRUE;
   1692 	above = NULL;
   1693 
   1694 	  /* set up the first field as the current... */
   1695 	cur = CIRCLEQ_FIRST(&form->sorted_fields);
   1696 	cur_row = cur->form_row;
   1697 
   1698 	  /* find the first field on the next row if any */
   1699 	below = CIRCLEQ_NEXT(cur, glue);
   1700 	below_row = -1;
   1701 	end_below = TRUE;
   1702 	real_end = TRUE;
   1703 	while (below != (void *)&form->sorted_fields) {
   1704 		if (below->form_row != cur_row) {
   1705 			below_row = below->form_row;
   1706 			end_below = FALSE;
   1707 			real_end = FALSE;
   1708 			break;
   1709 		}
   1710 		below = CIRCLEQ_NEXT(below, glue);
   1711 	}
   1712 
   1713 	  /* walk the sorted fields, setting the neighbour pointers */
   1714 	while (cur != (void *) &form->sorted_fields) {
   1715 		if (cur == CIRCLEQ_FIRST(&form->sorted_fields))
   1716 			cur->left = NULL;
   1717 		else
   1718 			cur->left = CIRCLEQ_PREV(cur, glue);
   1719 
   1720 		if (cur == CIRCLEQ_LAST(&form->sorted_fields))
   1721 			cur->right = NULL;
   1722 		else
   1723 			cur->right = CIRCLEQ_NEXT(cur, glue);
   1724 
   1725 		if (end_above == TRUE)
   1726 			cur->up = NULL;
   1727 		else {
   1728 			cur->up = above;
   1729 			above = CIRCLEQ_NEXT(above, glue);
   1730 			if (above_row != above->form_row) {
   1731 				end_above = TRUE;
   1732 				above_row = above->form_row;
   1733 			}
   1734 		}
   1735 
   1736 		if (end_below == TRUE)
   1737 			cur->down = NULL;
   1738 		else {
   1739 			cur->down = below;
   1740 			below = CIRCLEQ_NEXT(below, glue);
   1741 			if (below == (void *) &form->sorted_fields) {
   1742 				end_below = TRUE;
   1743 				real_end = TRUE;
   1744 			} else if (below_row != below->form_row) {
   1745 				end_below = TRUE;
   1746 				below_row = below->form_row;
   1747 			}
   1748 		}
   1749 
   1750 		cur = CIRCLEQ_NEXT(cur, glue);
   1751 		if ((cur != (void *) &form->sorted_fields)
   1752 		    && (cur_row != cur->form_row)) {
   1753 			cur_row = cur->form_row;
   1754 			if (end_above == FALSE) {
   1755 				for (; above != CIRCLEQ_FIRST(&form->sorted_fields);
   1756 				     above = CIRCLEQ_NEXT(above, glue)) {
   1757 					if (above->form_row != above_row) {
   1758 						above_row = above->form_row;
   1759 						break;
   1760 					}
   1761 				}
   1762 			} else if (above == NULL) {
   1763 				above = CIRCLEQ_FIRST(&form->sorted_fields);
   1764 				end_above = FALSE;
   1765 				above_row = above->form_row;
   1766 			} else
   1767 				end_above = FALSE;
   1768 
   1769 			if (end_below == FALSE) {
   1770 				while (below_row == below->form_row) {
   1771 					below = CIRCLEQ_NEXT(below,
   1772 							     glue);
   1773 					if (below ==
   1774 					    (void *)&form->sorted_fields) {
   1775 						real_end = TRUE;
   1776 						end_below = TRUE;
   1777 						break;
   1778 					}
   1779 				}
   1780 
   1781 				if (below != (void *)&form->sorted_fields)
   1782 					below_row = below->form_row;
   1783 			} else if (real_end == FALSE)
   1784 				end_below = FALSE;
   1785 
   1786 		}
   1787 	}
   1788 }
   1789