xref: /netbsd-src/lib/libform/internals.c (revision 17dd36da8292193180754d5047c0926dbb56818c)
1 /*	$NetBSD: internals.c,v 1.13 2001/03/25 12:32:53 blymn Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998-1999 Brett Lymn
5  *                         (blymn@baea.com.au, brett_lymn@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->hscroll + 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, sol, eol, npos, start, dest;
332 
333 	npos = pos;
334 
335 	if ((direction == JOIN_NEXT) || (direction == JOIN_NEXT_NW)) {
336 		sol = _formi_find_bol(str, pos);
337 		npos++;
338 		  /* see if there is another line following... */
339 		if (str[npos] == '\0')
340 			return E_REQUEST_DENIED;
341 		eol = _formi_find_eol(str, npos);
342 
343 		start = npos;
344 		dest = pos;
345 		len = eol - npos;
346 	} else {
347 		if (pos == 0)
348 			return E_REQUEST_DENIED;
349 		eol = _formi_find_eol(str, pos);
350 		npos--;
351 		sol = _formi_find_bol(str, npos);
352 
353 		start = pos;
354 		dest = npos;
355 		len = eol - pos;
356 	}
357 
358 
359 	bcopy(&str[start], &str[dest], (unsigned) len);
360 
361 	  /* wrap the field if required, if this fails undo the change */
362 	if ((direction == JOIN_NEXT) || (direction == JOIN_PREV)) {
363 		if (_formi_wrap_field(field, (unsigned int) pos) != E_OK) {
364 			bcopy(&str[dest], &str[start], (unsigned) len);
365 			str[dest] = '\n';
366 			return E_REQUEST_DENIED;
367 		}
368 	}
369 
370 	return E_OK;
371 }
372 
373 /*
374  * skip the blanks in the given string, start at the index start and
375  * continue forward until either the end of the string or a non-blank
376  * character is found.  Return the index of either the end of the string or
377  * the first non-blank character.
378  */
379 unsigned
380 _formi_skip_blanks(char *string, unsigned int start)
381 {
382 	unsigned int i;
383 
384 	i = start;
385 
386 	while ((string[i] != '\0') && isblank(string[i]))
387 		i++;
388 
389 	return i;
390 }
391 
392 /*
393  * Return the index of the top left most field of the two given fields.
394  */
395 static int
396 _formi_top_left(FORM *form, int a, int b)
397 {
398 	  /* lower row numbers always win here.... */
399 	if (form->fields[a]->form_row < form->fields[b]->form_row)
400 		return a;
401 
402 	if (form->fields[a]->form_row > form->fields[b]->form_row)
403 		return b;
404 
405 	  /* rows must be equal, check columns */
406 	if (form->fields[a]->form_col < form->fields[b]->form_col)
407 		return a;
408 
409 	if (form->fields[a]->form_col > form->fields[b]->form_col)
410 		return b;
411 
412 	  /* if we get here fields must be in exactly the same place, punt */
413 	return a;
414 }
415 
416 /*
417  * Return the index to the field that is the bottom-right-most of the
418  * two given fields.
419  */
420 static int
421 _formi_bottom_right(FORM *form, int a, int b)
422 {
423 	  /* check the rows first, biggest row wins */
424 	if (form->fields[a]->form_row > form->fields[b]->form_row)
425 		return a;
426 	if (form->fields[a]->form_row < form->fields[b]->form_row)
427 		return b;
428 
429 	  /* rows must be equal, check cols, biggest wins */
430 	if (form->fields[a]->form_col > form->fields[b]->form_col)
431 		return a;
432 	if (form->fields[a]->form_col < form->fields[b]->form_col)
433 		return b;
434 
435 	  /* fields in the same place, punt */
436 	return a;
437 }
438 
439 /*
440  * Find the next '\n' character in the given string starting at offset
441  * if there are no newlines found then return the index to the end of the
442  * string.
443  */
444 int
445 _formi_find_eol(const char *string, unsigned int offset)
446 {
447 	char *location;
448 	int eol;
449 
450 	if ((location = index(&string[offset], '\n')) != NULL)
451 		eol  = location - string;
452 	else
453 		eol = strlen(string);
454 
455 	if (eol > 0)
456 		eol--;
457 
458 	return eol;
459 }
460 
461 /*
462  * Find the previous '\n' character in the given string starting at offset
463  * if there are no newlines found then return 0.
464  */
465 int
466 _formi_find_bol(const char *string, unsigned int offset)
467 {
468 	int cnt;
469 
470 	cnt = offset;
471 	while ((cnt > 0) && (string[cnt] != '\n'))
472 		cnt--;
473 
474 	  /* if we moved and found a newline go forward one to point at the
475 	   * actual start of the line....
476 	   */
477 	if ((cnt != offset) && (string[cnt] == '\n'))
478 		cnt++;
479 
480 	return cnt;
481 }
482 
483 /*
484  * Find the end of the current word in the string str, starting at
485  * offset - the end includes any trailing whitespace.  If the end of
486  * the string is found before a new word then just return the offset
487  * to the end of the string.
488  */
489 static int
490 find_eow(char *str, unsigned int offset)
491 {
492 	int start;
493 
494 	start = offset;
495 	  /* first skip any non-whitespace */
496 	while ((str[start] != '\0') && !isblank(str[start]))
497 		start++;
498 
499 	  /* see if we hit the end of the string */
500 	if (str[start] == '\0')
501 		return start;
502 
503 	  /* otherwise skip the whitespace.... */
504 	while ((str[start] != '\0') && isblank(str[start]))
505 		start++;
506 
507 	return start;
508 }
509 
510 /*
511  * Find the beginning of the current word in the string str, starting
512  * at offset.
513  */
514 static int
515 find_sow(char *str, unsigned int offset)
516 {
517 	int start;
518 
519 	start = offset;
520 
521 	if (start > 0) {
522 		if (isblank(str[start]) || isblank(str[start - 1])) {
523 			if (isblank(str[start - 1]))
524 				start--;
525 			  /* skip the whitespace.... */
526 			while ((start >= 0) && isblank(str[start]))
527 				start--;
528 		}
529 	}
530 
531 	  /* see if we hit the start of the string */
532 	if (start < 0)
533 		return 0;
534 
535 	  /* now skip any non-whitespace */
536 	while ((start >= 0) && !isblank(str[start]))
537 		start--;
538 
539 	if (start > 0)
540 		start++; /* last loop has us pointing at a space, adjust */
541 
542 	if (start < 0)
543 		start = 0;
544 
545 	return start;
546 }
547 
548 /*
549  * Scroll the field forward the given number of lines.
550  */
551 static void
552 _formi_scroll_fwd(FIELD *field, unsigned int amt)
553 {
554 	  /* check if we have lines to scroll */
555 	if (field->row_count < (field->start_line + field->rows))
556 		return;
557 
558 	field->start_line += min(amt,
559 				 field->row_count - field->start_line
560 				 - field->rows);
561 }
562 
563 /*
564  * Scroll the field backward the given number of lines.
565  */
566 static void
567 _formi_scroll_back(FIELD *field, unsigned int amt)
568 {
569 	if (field->start_line == 0)
570 		return;
571 
572 	field->start_line -= min(field->start_line, amt);
573 }
574 
575 /*
576  * Scroll the field forward the given number of characters.
577  */
578 void
579 _formi_hscroll_fwd(FIELD *field, int unsigned amt)
580 {
581 	int end, scroll_amt;
582 
583 	end = _formi_find_eol(field->buffers[0].string,
584 		       field->start_char + field->hscroll
585 		       + field->cursor_xpos) - field->start_char
586 		- field->hscroll - field->cursor_xpos;
587 
588 	scroll_amt = min(amt, end);
589 	if (scroll_amt < 0)
590 		scroll_amt = 0;
591 
592 	field->hscroll += scroll_amt;
593 	if (amt > field->cursor_xpos)
594 		field->cursor_xpos = 0;
595 	else
596 		field->cursor_xpos -= scroll_amt;
597 }
598 
599 /*
600  * Scroll the field backward the given number of characters.
601  */
602 void
603 _formi_hscroll_back(FIELD *field, unsigned int amt)
604 {
605 	int flen, sa;
606 
607 	sa = min(field->hscroll, amt);
608 	field->hscroll -= sa;
609 	field->cursor_xpos += sa;
610 	flen = field->cols;
611 	if (field->start_char > 0)
612 		flen--;
613 	if (field->cursor_xpos > flen)
614 		field->cursor_xpos = flen;
615 }
616 
617 /*
618  * Find the different pages in the form fields and assign the form
619  * page_starts array with the information to find them.
620  */
621 int
622 _formi_find_pages(FORM *form)
623 {
624 	int i, cur_page = 0;
625 
626 	if ((form->page_starts = (_FORMI_PAGE_START *)
627 	     malloc((form->max_page + 1) * sizeof(_FORMI_PAGE_START))) == NULL)
628 		return E_SYSTEM_ERROR;
629 
630 	  /* initialise the page starts array */
631 	memset(form->page_starts, 0,
632 	       (form->max_page + 1) * sizeof(_FORMI_PAGE_START));
633 
634 	for (i =0; i < form->field_count; i++) {
635 		if (form->fields[i]->page_break == 1)
636 			cur_page++;
637 		if (form->page_starts[cur_page].in_use == 0) {
638 			form->page_starts[cur_page].in_use = 1;
639 			form->page_starts[cur_page].first = i;
640 			form->page_starts[cur_page].last = i;
641 			form->page_starts[cur_page].top_left = i;
642 			form->page_starts[cur_page].bottom_right = i;
643 		} else {
644 			form->page_starts[cur_page].last = i;
645 			form->page_starts[cur_page].top_left =
646 				_formi_top_left(form,
647 						form->page_starts[cur_page].top_left,
648 						i);
649 			form->page_starts[cur_page].bottom_right =
650 				_formi_bottom_right(form,
651 						    form->page_starts[cur_page].bottom_right,
652 						    i);
653 		}
654 	}
655 
656 	return E_OK;
657 }
658 
659 /*
660  * Completely redraw the field of the given form.
661  */
662 void
663 _formi_redraw_field(FORM *form, int field)
664 {
665 	unsigned int pre, post, flen, slen, i, row, start, end, offset;
666 	char *str;
667 	FIELD *cur;
668 #ifdef DEBUG
669 	char buffer[100];
670 #endif
671 
672 	cur = form->fields[field];
673 	str = cur->buffers[0].string;
674 	flen = cur->cols;
675 	slen = 0;
676 	start = 0;
677 	end = 0;
678 
679 	wmove(form->scrwin, (int) cur->form_row, (int) cur->form_col);
680 	for (row = 1; row <= cur->row_count; row++) {
681 		if (str == NULL) {
682 			start = end = 0;
683 		} else {
684 			if ((str[end] == '\0') || (str[end + 1] == '\0')
685 			    || (row == 1))
686 				start = end;
687 			else
688 				start = end + 1;
689 		}
690 
691 		if (cur->buffers[0].length > 0) {
692 			end = _formi_find_eol(str, start);
693 			slen = end - start + 1;
694 		} else
695 			slen = 0;
696 
697 		if ((cur->opts & O_STATIC) == O_STATIC) {
698 			switch (cur->justification) {
699 			case JUSTIFY_RIGHT:
700 				post = 0;
701 				if (flen < slen)
702 					pre = 0;
703 				else
704 					pre = flen - slen;
705 				break;
706 
707 			case JUSTIFY_CENTER:
708 				if (flen < slen) {
709 					pre = 0;
710 					post = 0;
711 				} else {
712 					pre = flen - slen;
713 					post = pre = pre / 2;
714 					  /* get padding right if
715                                              centring is not even */
716 					if ((post + pre + slen) < flen)
717 						post++;
718 				}
719 				break;
720 
721 			case NO_JUSTIFICATION:
722 			case JUSTIFY_LEFT:
723 			default:
724 				pre = 0;
725 				if (flen <= slen)
726 					post = 0;
727 				else {
728 					post = flen - slen;
729 					if (post > flen)
730 						post = flen;
731 				}
732 				break;
733 			}
734 
735 			offset = 0;
736 		} else {
737 			  /* dynamic fields are not justified */
738 			pre = 0;
739 			if (flen <= slen)
740 				post = 0;
741 			else {
742 				post = flen - slen;
743 				if (post > flen)
744 					post = flen;
745 			}
746 
747 			  /* but they do scroll.... */
748 
749 			if (pre > cur->hscroll - start)
750 				pre = pre - cur->hscroll + start;
751 			else
752 				pre = 0;
753 
754 			if (slen > cur->hscroll) {
755 				slen -= cur->hscroll;
756 				post += cur->hscroll;
757 				if (post > flen)
758 					post = flen;
759 			} else {
760 				slen = 0;
761 				post = flen - pre;
762 			}
763 
764 			offset = cur->hscroll;
765 			if (cur->start_char > 0)
766 				offset += cur->start_char - 1;
767 
768 			if (flen > cur->hscroll + 1) {
769 				if (flen > slen)
770 					flen -= cur->hscroll + 1;
771 			} else
772 				flen = 0;
773 
774 		}
775 
776 		if (form->cur_field == field)
777 			wattrset(form->scrwin, cur->fore);
778 		else
779 			wattrset(form->scrwin, cur->back);
780 
781 #ifdef DEBUG
782 		if (_formi_create_dbg_file() == E_OK) {
783 			fprintf(dbg,
784      "redraw_field: start=%d, pre=%d, slen=%d, flen=%d, post=%d, hscroll=%d\n",
785 				start, pre, slen, flen, post, cur->hscroll);
786 			if (str != NULL) {
787 				strncpy(buffer, &str[cur->start_char], flen);
788 			} else {
789 				strcpy(buffer, "(null)");
790 			}
791 			buffer[flen] = '\0';
792 			fprintf(dbg, "redraw_field: %s\n", buffer);
793 		}
794 #endif
795 
796 		for (i = start + cur->hscroll; i < pre; i++)
797 			waddch(form->scrwin, cur->pad);
798 
799 #ifdef DEBUG
800 		fprintf(dbg, "redraw_field: will add %d chars, offset is %d\n",
801 			min(slen, flen), offset);
802 #endif
803 		for (i = 0; i < min(slen, flen); i++)
804 		{
805 #ifdef DEBUG
806 			fprintf(dbg, "adding char str[%d]=%c\n",
807 				i + offset, str[i + offset]);
808 #endif
809 			if (((cur->opts & O_PUBLIC) != O_PUBLIC)) {
810 				waddch(form->scrwin, cur->pad);
811 			} else if ((cur->opts & O_VISIBLE) == O_VISIBLE) {
812 				waddch(form->scrwin, str[i + offset]);
813 			} else {
814 				waddch(form->scrwin, ' ');
815 			}
816 		}
817 
818 		for (i = 0; i < post; i++)
819 			waddch(form->scrwin, cur->pad);
820 	}
821 
822 	return;
823 }
824 
825 /*
826  * Display the fields attached to the form that are on the current page
827  * on the screen.
828  *
829  */
830 int
831 _formi_draw_page(FORM *form)
832 {
833 	int i;
834 
835 	if (form->page_starts[form->page].in_use == 0)
836 		return E_BAD_ARGUMENT;
837 
838 	wclear(form->scrwin);
839 
840 	for (i = form->page_starts[form->page].first;
841 	     i <= form->page_starts[form->page].last; i++)
842 		_formi_redraw_field(form, i);
843 
844 	return E_OK;
845 }
846 
847 /*
848  * Add the character c at the position pos in buffer 0 of the given field
849  */
850 int
851 _formi_add_char(FIELD *field, unsigned int pos, char c)
852 {
853 	char *new;
854 	unsigned int new_size;
855 	int status;
856 
857 	  /*
858 	   * If buffer has not had a string before, set it to a blank
859 	   * string.  Everything should flow from there....
860 	   */
861 	if (field->buffers[0].string == NULL) {
862 		set_field_buffer(field, 0, "");
863 	}
864 
865 	if (_formi_validate_char(field, c) != E_OK) {
866 #ifdef DEBUG
867 		fprintf(dbg, "add_char: char %c failed char validation\n", c);
868 #endif
869 		return E_INVALID_FIELD;
870 	}
871 
872 #ifdef DEBUG
873 	fprintf(dbg, "add_char: pos=%d, char=%c\n", pos, c);
874 	fprintf(dbg,
875 	   "add_char enter: xpos=%d, start=%d, length=%d(%d), allocated=%d\n",
876 		field->cursor_xpos, field->start_char,
877 		field->buffers[0].length, strlen(field->buffers[0].string),
878 		field->buffers[0].allocated);
879 	fprintf(dbg, "add_char enter: %s\n", field->buffers[0].string);
880 	fprintf(dbg, "add_char enter: buf0_status=%d\n", field->buf0_status);
881 #endif
882 	if (((field->opts & O_BLANK) == O_BLANK) &&
883 	    (field->buf0_status == FALSE) &&
884 	    ((field->cursor_xpos + field->hscroll) == 0)) {
885 		field->buffers[0].length = 0;
886 		field->buffers[0].string[0] = '\0';
887 		pos = 0;
888 		field->start_char = 0;
889 		field->start_line = 0;
890 		field->hscroll = 0;
891 		field->row_count = 1;
892 		field->cursor_xpos = 0;
893 		field->cursor_ypos = 0;
894 	}
895 
896 
897 	if ((field->overlay == 0)
898 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
899 		  /* first check if the field can have more chars...*/
900 		if ((((field->opts & O_STATIC) == O_STATIC) &&
901 		     (field->buffers[0].length >= field->cols)) ||
902 		    (((field->opts & O_STATIC) != O_STATIC) &&
903 /*XXXXX this is wrong - should check max row or col */		     ((field->max > 0) &&
904 		      (field->buffers[0].length >= field->max))))
905 			return E_REQUEST_DENIED;
906 
907 		if (field->buffers[0].length + 1
908 		    >= field->buffers[0].allocated) {
909 			new_size = field->buffers[0].allocated + 64
910 				- (field->buffers[0].allocated % 64);
911 			if ((new = (char *) realloc(field->buffers[0].string,
912 						    new_size )) == NULL)
913 				return E_SYSTEM_ERROR;
914 			field->buffers[0].allocated = new_size;
915 			field->buffers[0].string = new;
916 		}
917 	}
918 
919 	if ((field->overlay == 0) && (field->buffers[0].length > pos)) {
920 		bcopy(&field->buffers[0].string[pos],
921 		      &field->buffers[0].string[pos + 1],
922 		      field->buffers[0].length - pos + 1);
923 	}
924 
925 	field->buffers[0].string[pos] = c;
926 	if (pos >= field->buffers[0].length) {
927 		  /* make sure the string is terminated if we are at the
928 		   * end of the string, the terminator would be missing
929 		   * if we are are at the end of the field.
930 		   */
931 		field->buffers[0].string[pos + 1] = '\0';
932 	}
933 
934 	  /* only increment the length if we are inserting characters
935 	   * OR if we are at the end of the field in overlay mode.
936 	   */
937 	if ((field->overlay == 0)
938 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length)))
939 			field->buffers[0].length++;
940 
941 	  /* wrap the field, if needed */
942 	status = _formi_wrap_field(field, pos);
943 	if (status != E_OK) {
944 		  /* wrap failed for some reason, back out the char insert */
945 		bcopy(&field->buffers[0].string[pos + 1],
946 		      &field->buffers[0].string[pos],
947 		      field->buffers[0].length - pos);
948 		field->buffers[0].length--;
949 	} else {
950 		field->buf0_status = TRUE;
951 		field->cursor_xpos++;
952 		if (field->cursor_xpos > field->cols) {
953 			field->start_char++;
954 			field->cursor_xpos = field->cols;
955 		}
956 	}
957 
958 #ifdef DEBUG
959 	fprintf(dbg,
960 	    "add_char exit: xpos=%d, start=%d, length=%d(%d), allocated=%d\n",
961 		field->cursor_xpos, field->start_char,
962 		field->buffers[0].length, strlen(field->buffers[0].string),
963 		field->buffers[0].allocated);
964 	fprintf(dbg,"add_char exit: %s\n", field->buffers[0].string);
965 	fprintf(dbg, "add_char exit: buf0_status=%d\n", field->buf0_status);
966 	fprintf(dbg, "add_char exit: status = %s\n",
967 		(status == E_OK)? "OK" : "FAILED");
968 #endif
969 	return status;
970 }
971 
972 /*
973  * Manipulate the text in a field, this takes the given form and performs
974  * the passed driver command on the current text field.  Returns 1 if the
975  * text field was modified.
976  */
977 int
978 _formi_manipulate_field(FORM *form, int c)
979 {
980 	FIELD *cur;
981 	char *str;
982 	unsigned int i, start, end, pos;
983 
984 	cur = form->fields[form->cur_field];
985 
986 #ifdef DEBUG
987 	fprintf(dbg,
988 		"entry: xpos=%d, start_char=%d, length=%d, allocated=%d\n",
989 		cur->cursor_xpos, cur->start_char, cur->buffers[0].length,
990 		cur->buffers[0].allocated);
991 	fprintf(dbg, "entry: string=");
992 	if (cur->buffers[0].string == NULL)
993 		fprintf(dbg, "(null)\n");
994 	else
995 		fprintf(dbg, "\"%s\"\n", cur->buffers[0].string);
996 #endif
997 
998 	  /* Cannot manipulate a null string! */
999 	if (cur->buffers[0].string == NULL)
1000 		return E_REQUEST_DENIED;
1001 
1002 	switch (c) {
1003 	case REQ_NEXT_CHAR:
1004 		if ((cur->cursor_xpos + cur->start_char
1005 		     - ((cur->start_char > 0)? 1 : 0) + cur->hscroll + 1)
1006 		    > cur->buffers[0].length) {
1007 			return E_REQUEST_DENIED;
1008 		}
1009 		cur->cursor_xpos++;
1010 		if (cur->cursor_xpos >= cur->cols - cur->hscroll - 1) {
1011 			if (cur->cols < (cur->hscroll  + 1))
1012 				cur->cursor_xpos = 0;
1013 			else
1014 				cur->cursor_xpos = cur->cols
1015 					- cur->hscroll - 1;
1016 			cur->start_char++;
1017 		}
1018 		break;
1019 
1020 	case REQ_PREV_CHAR:
1021 		if (cur->cursor_xpos == 0) {
1022 			if (cur->start_char > 0)
1023 				cur->start_char--;
1024 			else if (cur->hscroll > 0)
1025 				cur->hscroll--;
1026 			else
1027 				return E_REQUEST_DENIED;
1028 		} else
1029 			cur->cursor_xpos--;
1030 		break;
1031 
1032 	case REQ_NEXT_LINE:
1033 		cur->cursor_ypos++;
1034 		if (cur->cursor_ypos > cur->rows) {
1035 			if ((cur->opts & O_STATIC) == O_STATIC) {
1036 				if (cur->start_line + cur->cursor_ypos
1037 				    > cur->drows) {
1038 					cur->cursor_ypos--;
1039 					return E_REQUEST_DENIED;
1040 				}
1041 			} else {
1042 				if (cur->start_line + cur->cursor_ypos
1043 				    > cur->nrows + cur->rows) {
1044 					cur->cursor_ypos--;
1045 					return E_REQUEST_DENIED;
1046 				}
1047 			}
1048 			cur->start_line++;
1049 		}
1050 		break;
1051 
1052 	case REQ_PREV_LINE:
1053 		if (cur->cursor_ypos == 0) {
1054 			if (cur->start_line == 0)
1055 				return E_REQUEST_DENIED;
1056 			cur->start_line--;
1057 		} else
1058 			cur->cursor_ypos--;
1059 		break;
1060 
1061 	case REQ_NEXT_WORD:
1062 		start = cur->start_char + cur->cursor_xpos;
1063 		str = cur->buffers[0].string;
1064 
1065 		start = find_eow(str, start);
1066 
1067 		  /* check if we hit the end */
1068 		if (str[start] == '\0')
1069 			return E_REQUEST_DENIED;
1070 
1071 		  /* otherwise we must have found the start of a word...*/
1072 		if (start - cur->start_char < cur->cols) {
1073 			cur->cursor_xpos = start;
1074 		} else {
1075 			cur->start_char = start;
1076 			cur->cursor_xpos = 0;
1077 		}
1078 		break;
1079 
1080 	case REQ_PREV_WORD:
1081 		start = cur->start_char + cur->cursor_xpos;
1082 		if (cur->start_char > 0)
1083 			start--;
1084 
1085 		if (start == 0)
1086 			return E_REQUEST_DENIED;
1087 
1088 		str = cur->buffers[0].string;
1089 
1090 		start = find_sow(str, start);
1091 
1092 		if (start - cur->start_char > 0) {
1093 			cur->cursor_xpos = start;
1094 		} else {
1095 			cur->start_char = start;
1096 			cur->cursor_xpos = 0;
1097 		}
1098 		break;
1099 
1100 	case REQ_BEG_FIELD:
1101 		cur->start_char = 0;
1102 		cur->start_line = 0;
1103 		cur->cursor_xpos = 0;
1104 		cur->cursor_ypos = 0;
1105 		break;
1106 
1107 	case REQ_END_FIELD:
1108 		if (cur->row_count > cur->rows) {
1109 			cur->start_line = cur->row_count - cur->rows;
1110 			cur->cursor_ypos = cur->rows - 1;
1111 		} else {
1112 			cur->start_line = 0;
1113 			cur->cursor_ypos = cur->row_count - 1;
1114 		}
1115 
1116 		if ((str = rindex(cur->buffers[0].string, '\n')) == NULL) {
1117 			cur->cursor_xpos = cur->cols - 1;
1118 			if (cur->start_char < (cur->buffers[0].length +
1119 					       cur->cols)) {
1120 				cur->start_char = 0;
1121 				cur->cursor_xpos = cur->buffers[0].length;
1122 			} else {
1123 				cur->start_char = cur->buffers[0].length -
1124 					cur->cols;
1125 			}
1126 		} else {
1127 			cur->start_char = (str - cur->buffers[0].string);
1128 			if (strlen(str) > cur->cols)
1129 				cur->cursor_xpos = cur->cols;
1130 			else
1131 				cur->cursor_xpos = strlen(str);
1132 		}
1133 		break;
1134 
1135 	case REQ_BEG_LINE:
1136 		start = cur->start_char + cur->cursor_xpos;
1137 		if (cur->buffers[0].string[start] == '\n') {
1138 			if (start > 0)
1139 				start--;
1140 			else
1141 				return E_REQUEST_DENIED;
1142 		}
1143 
1144 		while ((start > 0)
1145 		       && (cur->buffers[0].string[start] != '\n'))
1146 			start--;
1147 
1148 		if (start > 0)
1149 			start++;
1150 
1151 		cur->start_char = start;
1152 		cur->cursor_xpos = 0;
1153 		break;
1154 
1155 	case REQ_END_LINE:
1156 		start = cur->start_char + cur->cursor_xpos;
1157 		end = _formi_find_eol(cur->buffers[0].string, start);
1158 		start = _formi_find_bol(cur->buffers[0].string, start);
1159 
1160 		if (end - start > cur->cols - 1) {
1161 			cur->cursor_xpos = cur->cols - 1;
1162 			cur->start_char = end - cur->cols + 3;
1163 		} else {
1164 			cur->cursor_xpos = end - start + 1;
1165 			cur->start_char = start;
1166 		}
1167 		break;
1168 
1169 	case REQ_LEFT_CHAR:
1170 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0))
1171 			return E_REQUEST_DENIED;
1172 
1173 		if (cur->cursor_xpos == 0) {
1174 			cur->start_char--;
1175 			if (cur->buffers[0].string[cur->start_char] == '\n') {
1176 				if ((cur->cursor_ypos == 0) &&
1177 				    (cur->start_line == 0))
1178 				{
1179 					cur->start_char++;
1180 					return E_REQUEST_DENIED;
1181 				}
1182 
1183 				if (cur->cursor_ypos == 0)
1184 					cur->start_line--;
1185 				else
1186 					cur->cursor_ypos--;
1187 
1188 				end = _formi_find_eol(cur->buffers[0].string,
1189 					       cur->start_char);
1190 				start = _formi_find_bol(cur->buffers[0].string,
1191 						 cur->start_char);
1192 				if (end - start >= cur->cols) {
1193 					cur->cursor_xpos = cur->cols - 1;
1194 					cur->start_char = end - cur->cols;
1195 				} else {
1196 					cur->cursor_xpos = end - start;
1197 					cur->start_char = start;
1198 				}
1199 			}
1200 		} else
1201 			cur->cursor_xpos--;
1202 		break;
1203 
1204 	case REQ_RIGHT_CHAR:
1205 		pos = cur->start_char + cur->cursor_xpos;
1206 		if (cur->buffers[0].string[pos] == '\0')
1207 			return E_REQUEST_DENIED;
1208 
1209 #ifdef DEBUG
1210 		fprintf(dbg, "req_right_char enter: start=%d, xpos=%d, c=%c\n",
1211 			cur->start_char, cur->cursor_xpos,
1212 			cur->buffers[0].string[pos]);
1213 #endif
1214 
1215 		if (cur->buffers[0].string[pos] == '\n') {
1216 			start = pos + 1;
1217 			if (cur->buffers[0].string[start] == 0)
1218 				return E_REQUEST_DENIED;
1219 			end = _formi_find_eol(cur->buffers[0].string, start);
1220 			if (end - start > cur->cols) {
1221 				cur->cursor_xpos = cur->cols - 1;
1222 				cur->start_char = end - cur->cols - 1;
1223 			} else {
1224 				cur->cursor_xpos = end - start;
1225 				cur->start_char = start;
1226 			}
1227 		} else {
1228 			if (cur->cursor_xpos == cur->cols - 1)
1229 				cur->start_char++;
1230 			else
1231 				cur->cursor_xpos++;
1232 		}
1233 #ifdef DEBUG
1234 		fprintf(dbg, "req_right_char exit: start=%d, xpos=%d, c=%c\n",
1235 			cur->start_char, cur->cursor_xpos,
1236 			cur->buffers[0].string[cur->start_char +
1237 					      cur->cursor_xpos]);
1238 #endif
1239 		break;
1240 
1241 	case REQ_UP_CHAR:
1242 		if (cur->cursor_ypos == 0) {
1243 			if (cur->start_line == 0)
1244 				return E_REQUEST_DENIED;
1245 
1246 			cur->start_line--;
1247 		} else
1248 			cur->cursor_ypos--;
1249 
1250 		start = find_cur_line(cur);
1251 		end = _formi_find_eol(cur->buffers[0].string, start);
1252 		cur->start_char = start;
1253 		if (cur->cursor_xpos > end - start)
1254 			cur->cursor_xpos = end - start;
1255 		break;
1256 
1257 	case REQ_DOWN_CHAR:
1258 		if (cur->cursor_ypos == cur->rows - 1) {
1259 			if (cur->start_line + cur->rows == cur->row_count)
1260 				return E_REQUEST_DENIED;
1261 			cur->start_line++;
1262 		} else
1263 			cur->cursor_ypos++;
1264 
1265 		start = find_cur_line(cur);
1266 		end = _formi_find_eol(cur->buffers[0].string, start);
1267 		cur->start_char = start;
1268 		if (cur->cursor_xpos > end - start)
1269 			cur->cursor_xpos = end - start;
1270 		break;
1271 
1272 	case REQ_NEW_LINE:
1273 		if (_formi_add_char(cur, cur->start_char + cur->cursor_xpos,
1274 				    '\n') == E_OK)
1275 			cur->row_count++;
1276 		break;
1277 
1278 	case REQ_INS_CHAR:
1279 		_formi_add_char(cur, cur->start_char + cur->cursor_xpos,
1280 				cur->pad);
1281 		break;
1282 
1283 	case REQ_INS_LINE:
1284 		start = _formi_find_bol(cur->buffers[0].string, cur->start_char);
1285 		if (_formi_add_char(cur, start, '\n') == E_OK)
1286 			cur->row_count++;
1287 		break;
1288 
1289 	case REQ_DEL_CHAR:
1290 		if (cur->buffers[0].string[cur->start_char + cur->cursor_xpos]
1291 		    == '\0')
1292 			return E_REQUEST_DENIED;
1293 
1294 		start = cur->start_char + cur->cursor_xpos;
1295 		end = cur->buffers[0].length;
1296 		if (cur->buffers[0].string[start] == '\n') {
1297 			if (cur->row_count > 1) {
1298 				cur->row_count--;
1299 				_formi_join_line(cur, cur->buffers[0].string,
1300 						 start, JOIN_NEXT);
1301 			} else
1302 				cur->buffers[0].string[start] = '\0';
1303 		} else {
1304 			bcopy(&cur->buffers[0].string[start + 1],
1305 			      &cur->buffers[0].string[start],
1306 			      (unsigned) end - start + 1);
1307 		}
1308 
1309 		cur->buffers[0].length--;
1310 		break;
1311 
1312 	case REQ_DEL_PREV:
1313 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0))
1314 			   return E_REQUEST_DENIED;
1315 
1316 		start = cur->cursor_xpos + cur->start_char;
1317 		end = cur->buffers[0].length;
1318 
1319 		if (cur->buffers[0].string[cur->start_char + cur->cursor_xpos] == '\n') {
1320 			_formi_join_line(cur, cur->buffers[0].string,
1321 					 cur->start_char + cur->cursor_xpos,
1322 					 JOIN_PREV);
1323 			cur->row_count--;
1324 		} else {
1325 			bcopy(&cur->buffers[0].string[start],
1326 			      &cur->buffers[0].string[start - 1],
1327 			      (unsigned) end - start + 1);
1328 		}
1329 
1330 		cur->buffers[0].length--;
1331 		if ((cur->cursor_xpos == 0) && (cur->start_char > 0))
1332 			cur->start_char--;
1333 		else if ((cur->cursor_xpos == cur->cols - 1)
1334 			 && (cur->start_char > 0))
1335 			cur->start_char--;
1336 		else if (cur->cursor_xpos > 0)
1337 			cur->cursor_xpos--;
1338 
1339 		break;
1340 
1341 	case REQ_DEL_LINE:
1342 		start = cur->start_char + cur->cursor_xpos;
1343 		end = _formi_find_eol(cur->buffers[0].string, start);
1344 		start = _formi_find_bol(cur->buffers[0].string, start);
1345 		bcopy(&cur->buffers[0].string[end + 1],
1346 		      &cur->buffers[0].string[start],
1347 		      (unsigned) cur->buffers[0].length - end + 1);
1348 		if (cur->row_count > 1)
1349 			cur->row_count--;
1350 		break;
1351 
1352 	case REQ_DEL_WORD:
1353 		start = cur->start_char + cur->cursor_xpos;
1354 		end = find_eow(cur->buffers[0].string, start);
1355 		start = find_sow(cur->buffers[0].string, start);
1356 		bcopy(&cur->buffers[0].string[end + 1],
1357 		      &cur->buffers[0].string[start],
1358 		      (unsigned) cur->buffers[0].length - end + 1);
1359 		cur->buffers[0].length -= end - start;
1360 		break;
1361 
1362 	case REQ_CLR_EOL:
1363 		  /*XXXX this right or should we just toast the chars? */
1364 		start = cur->start_char + cur->cursor_xpos;
1365 		end = _formi_find_eol(cur->buffers[0].string, start);
1366 		for (i = start; i < end; i++)
1367 			cur->buffers[0].string[i] = cur->pad;
1368 		break;
1369 
1370 	case REQ_CLR_EOF:
1371 		for (i = cur->start_char + cur->cursor_xpos;
1372 		     i < cur->buffers[0].length; i++)
1373 			cur->buffers[0].string[i] = cur->pad;
1374 		break;
1375 
1376 	case REQ_CLR_FIELD:
1377 		for (i = 0; i < cur->buffers[0].length; i++)
1378 			cur->buffers[0].string[i] = cur->pad;
1379 		break;
1380 
1381 	case REQ_OVL_MODE:
1382 		cur->overlay = 1;
1383 		break;
1384 
1385 	case REQ_INS_MODE:
1386 		cur->overlay = 0;
1387 		break;
1388 
1389 	case REQ_SCR_FLINE:
1390 		_formi_scroll_fwd(cur, 1);
1391 		break;
1392 
1393 	case REQ_SCR_BLINE:
1394 		_formi_scroll_back(cur, 1);
1395 		break;
1396 
1397 	case REQ_SCR_FPAGE:
1398 		_formi_scroll_fwd(cur, cur->rows);
1399 		break;
1400 
1401 	case REQ_SCR_BPAGE:
1402 		_formi_scroll_back(cur, cur->rows);
1403 		break;
1404 
1405 	case REQ_SCR_FHPAGE:
1406 		_formi_scroll_fwd(cur, cur->rows / 2);
1407 		break;
1408 
1409 	case REQ_SCR_BHPAGE:
1410 		_formi_scroll_back(cur, cur->rows / 2);
1411 		break;
1412 
1413 	case REQ_SCR_FCHAR:
1414 		_formi_hscroll_fwd(cur, 1);
1415 		break;
1416 
1417 	case REQ_SCR_BCHAR:
1418 		_formi_hscroll_back(cur, 1);
1419 		break;
1420 
1421 	case REQ_SCR_HFLINE:
1422 		_formi_hscroll_fwd(cur, cur->cols);
1423 		break;
1424 
1425 	case REQ_SCR_HBLINE:
1426 		_formi_hscroll_back(cur, cur->cols);
1427 		break;
1428 
1429 	case REQ_SCR_HFHALF:
1430 		_formi_hscroll_fwd(cur, cur->cols / 2);
1431 		break;
1432 
1433 	case REQ_SCR_HBHALF:
1434 		_formi_hscroll_back(cur, cur->cols / 2);
1435 		break;
1436 
1437 	default:
1438 		return 0;
1439 	}
1440 
1441 #ifdef DEBUG
1442 	fprintf(dbg, "exit: xpos=%d, start_char=%d, length=%d, allocated=%d\n",
1443 		cur->cursor_xpos, cur->start_char, cur->buffers[0].length,
1444 		cur->buffers[0].allocated);
1445 	fprintf(dbg, "exit: string=\"%s\"\n", cur->buffers[0].string);
1446 #endif
1447 	return 1;
1448 }
1449 
1450 /*
1451  * Validate the give character by passing it to any type character
1452  * checking routines, if they exist.
1453  */
1454 int
1455 _formi_validate_char(FIELD *field, char c)
1456 {
1457 	int ret_val;
1458 
1459 	if (field->type == NULL)
1460 		return E_OK;
1461 
1462 	ret_val = E_INVALID_FIELD;
1463 	_formi_do_char_validation(field, field->type, c, &ret_val);
1464 
1465 	return ret_val;
1466 }
1467 
1468 
1469 /*
1470  * Perform the validation of the character, invoke all field_type validation
1471  * routines.  If the field is ok then update ret_val to E_OK otherwise
1472  * ret_val is not changed.
1473  */
1474 static void
1475 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val)
1476 {
1477 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
1478 		_formi_do_char_validation(field, type->link->next, c, ret_val);
1479 		_formi_do_char_validation(field, type->link->prev, c, ret_val);
1480 	} else {
1481 		if (type->char_check == NULL)
1482 			*ret_val = E_OK;
1483 		else {
1484 			if (type->char_check((int)(unsigned char) c,
1485 					     field->args) == TRUE)
1486 				*ret_val = E_OK;
1487 		}
1488 	}
1489 }
1490 
1491 /*
1492  * Validate the current field.  If the field validation returns success then
1493  * return E_OK otherwise return E_INVALID_FIELD.
1494  *
1495  */
1496 int
1497 _formi_validate_field(FORM *form)
1498 {
1499 	FIELD *cur;
1500 	char *bp;
1501 	int ret_val, count;
1502 
1503 
1504 	if ((form == NULL) || (form->fields == NULL) ||
1505 	    (form->fields[0] == NULL))
1506 		return E_INVALID_FIELD;
1507 
1508 	cur = form->fields[form->cur_field];
1509 
1510 	bp = cur->buffers[0].string;
1511 	count = _formi_skip_blanks(bp, 0);
1512 
1513 	  /* check if we have a null field, depending on the nullok flag
1514 	   * this may be acceptable or not....
1515 	   */
1516 	if (cur->buffers[0].string[count] == '\0') {
1517 		if ((cur->opts & O_NULLOK) == O_NULLOK)
1518 			return E_OK;
1519 		else
1520 			return E_INVALID_FIELD;
1521 	}
1522 
1523 	  /* check if an unmodified field is ok */
1524 	if (cur->buf0_status == 0) {
1525 		if ((cur->opts & O_PASSOK) == O_PASSOK)
1526 			return E_OK;
1527 		else
1528 			return E_INVALID_FIELD;
1529 	}
1530 
1531 	  /* if there is no type then just accept the field */
1532 	if (cur->type == NULL)
1533 		return E_OK;
1534 
1535 	ret_val = E_INVALID_FIELD;
1536 	_formi_do_validation(cur, cur->type, &ret_val);
1537 
1538 	return ret_val;
1539 }
1540 
1541 /*
1542  * Perform the validation of the field, invoke all field_type validation
1543  * routines.  If the field is ok then update ret_val to E_OK otherwise
1544  * ret_val is not changed.
1545  */
1546 static void
1547 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val)
1548 {
1549 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
1550 		_formi_do_validation(field, type->link->next, ret_val);
1551 		_formi_do_validation(field, type->link->prev, ret_val);
1552 	} else {
1553 		if (type->field_check == NULL)
1554 			*ret_val = E_OK;
1555 		else {
1556 			if (type->field_check(field, field_buffer(field, 0))
1557 			    == TRUE)
1558 				*ret_val = E_OK;
1559 		}
1560 	}
1561 }
1562 
1563 /*
1564  * Select the next/previous choice for the field, the driver command
1565  * selecting the direction will be passed in c.  Return 1 if a choice
1566  * selection succeeded, 0 otherwise.
1567  */
1568 int
1569 _formi_field_choice(FORM *form, int c)
1570 {
1571 	FIELDTYPE *type;
1572 	FIELD *field;
1573 
1574 	if ((form == NULL) || (form->fields == NULL) ||
1575 	    (form->fields[0] == NULL) ||
1576 	    (form->fields[form->cur_field]->type == NULL))
1577 		return 0;
1578 
1579 	field = form->fields[form->cur_field];
1580 	type = field->type;
1581 
1582 	switch (c) {
1583 	case REQ_NEXT_CHOICE:
1584 		if (type->next_choice == NULL)
1585 			return 0;
1586 		else
1587 			return type->next_choice(field,
1588 						 field_buffer(field, 0));
1589 
1590 	case REQ_PREV_CHOICE:
1591 		if (type->prev_choice == NULL)
1592 			return 0;
1593 		else
1594 			return type->prev_choice(field,
1595 						 field_buffer(field, 0));
1596 
1597 	default: /* should never happen! */
1598 		return 0;
1599 	}
1600 }
1601 
1602 /*
1603  * Update the fields if they have changed.  The parameter old has the
1604  * previous current field as the current field may have been updated by
1605  * the driver.  Return 1 if the form page needs updating.
1606  *
1607  */
1608 int
1609 _formi_update_field(FORM *form, int old_field)
1610 {
1611 	int cur, i;
1612 
1613 	cur = form->cur_field;
1614 
1615 	if (old_field != cur) {
1616 		if (!((cur >= form->page_starts[form->page].first) &&
1617 		      (cur <= form->page_starts[form->page].last))) {
1618 			  /* not on same page any more */
1619 			for (i = 0; i < form->max_page; i++) {
1620 				if ((form->page_starts[i].in_use == 1) &&
1621 				    (form->page_starts[i].first <= cur) &&
1622 				    (form->page_starts[i].last >= cur)) {
1623 					form->page = i;
1624 					return 1;
1625 				}
1626 			}
1627 		}
1628 	}
1629 
1630 	_formi_redraw_field(form, old_field);
1631 	_formi_redraw_field(form, form->cur_field);
1632 	return 0;
1633 }
1634 
1635 /*
1636  * Compare function for the field sorting
1637  *
1638  */
1639 static int
1640 field_sort_compare(const void *one, const void *two)
1641 {
1642 	const FIELD *a, *b;
1643 	int tl;
1644 
1645 	  /* LINTED const castaway; we don't modify these! */
1646 	a = (const FIELD *) *((const FIELD **) one);
1647 	b = (const FIELD *) *((const FIELD **) two);
1648 
1649 	if (a == NULL)
1650 		return 1;
1651 
1652 	if (b == NULL)
1653 		return -1;
1654 
1655 	  /*
1656 	   * First check the page, we want the fields sorted by page.
1657 	   *
1658 	   */
1659 	if (a->page != b->page)
1660 		return ((a->page > b->page)? 1 : -1);
1661 
1662 	tl = _formi_top_left(a->parent, a->index, b->index);
1663 
1664 	  /*
1665 	   * sort fields left to right, top to bottom so the top left is
1666 	   * the less than value....
1667 	   */
1668 	return ((tl == a->index)? -1 : 1);
1669 }
1670 
1671 /*
1672  * Sort the fields in a form ready for driver traversal.
1673  */
1674 void
1675 _formi_sort_fields(FORM *form)
1676 {
1677 	FIELD **sort_area;
1678 	int i;
1679 
1680 	CIRCLEQ_INIT(&form->sorted_fields);
1681 
1682 	if ((sort_area = (FIELD **) malloc(sizeof(FIELD *) * form->field_count))
1683 	    == NULL)
1684 		return;
1685 
1686 	bcopy(form->fields, sort_area, sizeof(FIELD *) * form->field_count);
1687 	qsort(sort_area, (unsigned) form->field_count, sizeof(FIELD *),
1688 	      field_sort_compare);
1689 
1690 	for (i = 0; i < form->field_count; i++)
1691 		CIRCLEQ_INSERT_TAIL(&form->sorted_fields, sort_area[i], glue);
1692 
1693 	free(sort_area);
1694 }
1695 
1696 /*
1697  * Set the neighbours for all the fields in the given form.
1698  */
1699 void
1700 _formi_stitch_fields(FORM *form)
1701 {
1702 	int above_row, below_row, end_above, end_below, cur_row, real_end;
1703 	FIELD *cur, *above, *below;
1704 
1705 	  /*
1706 	   * check if the sorted fields circle queue is empty, just
1707 	   * return if it is.
1708 	   */
1709 	if (CIRCLEQ_EMPTY(&form->sorted_fields))
1710 		return;
1711 
1712 	  /* initially nothing is above..... */
1713 	above_row = -1;
1714 	end_above = TRUE;
1715 	above = NULL;
1716 
1717 	  /* set up the first field as the current... */
1718 	cur = CIRCLEQ_FIRST(&form->sorted_fields);
1719 	cur_row = cur->form_row;
1720 
1721 	  /* find the first field on the next row if any */
1722 	below = CIRCLEQ_NEXT(cur, glue);
1723 	below_row = -1;
1724 	end_below = TRUE;
1725 	real_end = TRUE;
1726 	while (below != (void *)&form->sorted_fields) {
1727 		if (below->form_row != cur_row) {
1728 			below_row = below->form_row;
1729 			end_below = FALSE;
1730 			real_end = FALSE;
1731 			break;
1732 		}
1733 		below = CIRCLEQ_NEXT(below, glue);
1734 	}
1735 
1736 	  /* walk the sorted fields, setting the neighbour pointers */
1737 	while (cur != (void *) &form->sorted_fields) {
1738 		if (cur == CIRCLEQ_FIRST(&form->sorted_fields))
1739 			cur->left = NULL;
1740 		else
1741 			cur->left = CIRCLEQ_PREV(cur, glue);
1742 
1743 		if (cur == CIRCLEQ_LAST(&form->sorted_fields))
1744 			cur->right = NULL;
1745 		else
1746 			cur->right = CIRCLEQ_NEXT(cur, glue);
1747 
1748 		if (end_above == TRUE)
1749 			cur->up = NULL;
1750 		else {
1751 			cur->up = above;
1752 			above = CIRCLEQ_NEXT(above, glue);
1753 			if (above_row != above->form_row) {
1754 				end_above = TRUE;
1755 				above_row = above->form_row;
1756 			}
1757 		}
1758 
1759 		if (end_below == TRUE)
1760 			cur->down = NULL;
1761 		else {
1762 			cur->down = below;
1763 			below = CIRCLEQ_NEXT(below, glue);
1764 			if (below == (void *) &form->sorted_fields) {
1765 				end_below = TRUE;
1766 				real_end = TRUE;
1767 			} else if (below_row != below->form_row) {
1768 				end_below = TRUE;
1769 				below_row = below->form_row;
1770 			}
1771 		}
1772 
1773 		cur = CIRCLEQ_NEXT(cur, glue);
1774 		if ((cur != (void *) &form->sorted_fields)
1775 		    && (cur_row != cur->form_row)) {
1776 			cur_row = cur->form_row;
1777 			if (end_above == FALSE) {
1778 				for (; above != CIRCLEQ_FIRST(&form->sorted_fields);
1779 				     above = CIRCLEQ_NEXT(above, glue)) {
1780 					if (above->form_row != above_row) {
1781 						above_row = above->form_row;
1782 						break;
1783 					}
1784 				}
1785 			} else if (above == NULL) {
1786 				above = CIRCLEQ_FIRST(&form->sorted_fields);
1787 				end_above = FALSE;
1788 				above_row = above->form_row;
1789 			} else
1790 				end_above = FALSE;
1791 
1792 			if (end_below == FALSE) {
1793 				while (below_row == below->form_row) {
1794 					below = CIRCLEQ_NEXT(below,
1795 							     glue);
1796 					if (below ==
1797 					    (void *)&form->sorted_fields) {
1798 						real_end = TRUE;
1799 						end_below = TRUE;
1800 						break;
1801 					}
1802 				}
1803 
1804 				if (below != (void *)&form->sorted_fields)
1805 					below_row = below->form_row;
1806 			} else if (real_end == FALSE)
1807 				end_below = FALSE;
1808 
1809 		}
1810 	}
1811 }
1812