xref: /netbsd-src/lib/libform/internals.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /*	$NetBSD: internals.c,v 1.29 2003/03/09 00:57:18 lukem 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 without 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 <sys/cdefs.h>
33 __RCSID("$NetBSD: internals.c,v 1.29 2003/03/09 00:57:18 lukem Exp $");
34 
35 #include <limits.h>
36 #include <ctype.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <strings.h>
40 #include <assert.h>
41 #include "internals.h"
42 #include "form.h"
43 
44 #ifdef DEBUG
45 /*
46  *  file handle to write debug info to, this will be initialised when
47  *  the form is first posted.
48  */
49 FILE *dbg = NULL;
50 
51 /*
52  * map the request numbers to strings for debug
53  */
54 char *reqs[] = {
55 	"NEXT_PAGE", "PREV_PAGE", "FIRST_PAGE",	"LAST_PAGE", "NEXT_FIELD",
56 	"PREV_FIELD", "FIRST_FIELD", "LAST_FIELD", "SNEXT_FIELD",
57 	"SPREV_FIELD", "SFIRST_FIELD", "SLAST_FIELD", "LEFT_FIELD",
58 	"RIGHT_FIELD", "UP_FIELD", "DOWN_FIELD", "NEXT_CHAR", "PREV_CHAR",
59 	"NEXT_LINE", "PREV_LINE", "NEXT_WORD", "PREV_WORD", "BEG_FIELD",
60 	"END_FIELD", "BEG_LINE", "END_LINE", "LEFT_CHAR", "RIGHT_CHAR",
61 	"UP_CHAR", "DOWN_CHAR", "NEW_LINE", "INS_CHAR", "INS_LINE",
62 	"DEL_CHAR", "DEL_PREV", "DEL_LINE", "DEL_WORD", "CLR_EOL",
63 	"CLR_EOF", "CLR_FIELD", "OVL_MODE", "INS_MODE", "SCR_FLINE",
64 	"SCR_BLINE", "SCR_FPAGE", "SCR_BPAGE", "SCR_FHPAGE", "SCR_BHPAGE",
65 	"SCR_FCHAR", "SCR_BCHAR", "SCR_HFLINE", "SCR_HBLINE", "SCR_HFHALF",
66 	"SCR_HBHALF", "VALIDATION", "PREV_CHOICE", "NEXT_CHOICE" };
67 #endif
68 
69 /* define our own min function - this is not generic but will do here
70  * (don't believe me?  think about what value you would get
71  * from min(x++, y++)
72  */
73 #define min(a,b) (((a) > (b))? (b) : (a))
74 
75 /* for the line joining function... */
76 #define JOIN_NEXT    1
77 #define JOIN_NEXT_NW 2 /* next join, don't wrap the joined line */
78 #define JOIN_PREV    3
79 #define JOIN_PREV_NW 4 /* previous join, don't wrap the joined line */
80 
81 /* for the bump_lines function... */
82 #define _FORMI_USE_CURRENT -1 /* indicates current cursor pos to be used */
83 
84 static void
85 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val);
86 static void
87 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val);
88 static int
89 _formi_join_line(FIELD *field, unsigned int pos, int direction);
90 void
91 _formi_hscroll_back(FIELD *field, unsigned int amt);
92 void
93 _formi_hscroll_fwd(FIELD *field, unsigned int amt);
94 static void
95 _formi_scroll_back(FIELD *field, unsigned int amt);
96 static void
97 _formi_scroll_fwd(FIELD *field, unsigned int amt);
98 static int
99 _formi_set_cursor_xpos(FIELD *field, int no_scroll);
100 static int
101 find_sow(char *str, unsigned int offset);
102 static int
103 find_cur_line(FIELD *cur, unsigned pos);
104 static int
105 split_line(FIELD *field, unsigned pos);
106 static void
107 bump_lines(FIELD *field, int pos, int amt, bool do_len);
108 static bool
109 check_field_size(FIELD *field);
110 static int
111 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c);
112 static int
113 tab_size(FIELD *field, unsigned int offset, unsigned int i);
114 static unsigned int
115 tab_fit_len(FIELD *field, unsigned int row, unsigned int len);
116 static int
117 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window);
118 
119 
120 /*
121  * Initialise the row offset for a field, depending on the type of
122  * field it is and the type of justification used.  The justification
123  * is only used on static single line fields, everything else will
124  * have the cursor_xpos set to 0.
125  */
126 void
127 _formi_init_field_xpos(FIELD *field)
128 {
129 	  /* not static or is multi-line which are not justified, so 0 it is */
130 	if (((field->opts & O_STATIC) != O_STATIC) ||
131 	    ((field->rows + field->nrows) != 1)) {
132 		field->cursor_xpos = 0;
133 		return;
134 	}
135 
136 	switch (field->justification) {
137 	case JUSTIFY_RIGHT:
138 		field->cursor_xpos = field->cols - 1;
139 		break;
140 
141 	case JUSTIFY_CENTER:
142 		field->cursor_xpos = (field->cols - 1) / 2;
143 		break;
144 
145 	default: /* assume left justify */
146 		field->cursor_xpos = 0;
147 		break;
148 	}
149 }
150 
151 
152 /*
153  * Open the debug file if it is not already open....
154  */
155 #ifdef DEBUG
156 int
157 _formi_create_dbg_file(void)
158 {
159 	if (dbg == NULL) {
160 		dbg = fopen("___form_dbg.out", "w");
161 		if (dbg == NULL) {
162 			fprintf(stderr, "Cannot open debug file!\n");
163 			return E_SYSTEM_ERROR;
164 		}
165 	}
166 
167 	return E_OK;
168 }
169 #endif
170 
171 /*
172  * Bump the lines array elements in the given field by the given amount.
173  * The row to start acting on can either be inferred from the given position
174  * or if the special value _FORMI_USE_CURRENT is set then the row will be
175  * the row the cursor is currently on.
176  */
177 static void
178 bump_lines(FIELD *field, int pos, int amt, bool do_len)
179 {
180 	int i, row, old_len;
181 #ifdef DEBUG
182 	int dbg_ok = FALSE;
183 #endif
184 
185 	if (pos == _FORMI_USE_CURRENT)
186 		row = field->start_line + field->cursor_ypos;
187 	else
188 		row = find_cur_line(field, (unsigned) pos);
189 
190 #ifdef DEBUG
191 	if (_formi_create_dbg_file() == E_OK) {
192 		dbg_ok = TRUE;
193 		fprintf(dbg, "bump_lines: bump starting at row %d\n", row);
194 		fprintf(dbg,
195 			"bump_lines: len from %d to %d, end from %d to %d\n",
196 			field->lines[row].length,
197 			field->lines[row].length + amt,
198 			field->lines[row].end, field->lines[row].end + amt);
199 	}
200 #endif
201 
202 	if (((int)field->lines[row].length + amt) < 0) {
203 		field->lines[row].length = 0;
204 		old_len = 0;
205 	} else {
206 		old_len = field->lines[row].length;
207 		if (do_len == TRUE) {
208 			field->lines[row].length =
209 				_formi_tab_expanded_length(
210 					&field->buffers[0].string[
211 						field->lines[row].start], 0,
212 					field->lines[row].end + amt
213 					    -field->lines[row].start);
214 		}
215 	}
216 
217 	if (old_len > 0) {
218 		if ((amt < 0) && (- amt > field->lines[row].end))
219 			field->lines[row].end = field->lines[row].start;
220 		else
221 			field->lines[row].end += amt;
222 	} else
223 		field->lines[row].end = field->lines[row].start;
224 
225 #ifdef DEBUG
226 	if (dbg_ok)
227 		fprintf(dbg, "bump_lines: expanded length %d\n",
228 			field->lines[row].length);
229 #endif
230 
231 	for (i = row + 1; i < field->row_count; i++) {
232 #ifdef DEBUG
233 		if (dbg_ok) {
234 			fprintf(dbg,
235 		"bump_lines: row %d: len from %d to %d, end from %d to %d\n",
236 				i, field->lines[i].start,
237 				field->lines[i].start + amt,
238 				field->lines[i].end,
239 				field->lines[i].end + amt);
240 		}
241 		fflush(dbg);
242 #endif
243 		field->lines[i].start += amt;
244 		field->lines[i].end += amt;
245 		field->lines[i].length = _formi_tab_expanded_length(
246 			&field->buffers[0].string[field->lines[i].start],
247 			0, field->lines[i].end - field->lines[i].start);
248 #ifdef DEBUG
249 		if (dbg_ok) {
250 			fprintf(dbg,
251 				"bump_lines: row %d, expanded length %d\n",
252 				i, field->lines[i].length);
253 		}
254 #endif
255 	}
256 }
257 
258 /*
259  * Check the sizing of the field, if the maximum size is set for a
260  * dynamic field then check that the number of rows or columns does
261  * not exceed the set maximum.  The decision to check the rows or
262  * columns is made on the basis of how many rows are in the field -
263  * one row means the max applies to the number of columns otherwise it
264  * applies to the number of rows.  If the row/column count is less
265  * than the maximum then return TRUE.
266  *
267  */
268 static bool
269 check_field_size(FIELD *field)
270 {
271 	if ((field->opts & O_STATIC) != O_STATIC) {
272 		  /* dynamic field */
273 		if (field->max == 0) /* unlimited */
274 			return TRUE;
275 
276 		if (field->rows == 1) {
277 			return (field->buffers[0].length < field->max);
278 		} else {
279 			return (field->row_count <= field->max);
280 		}
281 	} else {
282 		if ((field->rows + field->nrows) == 1) {
283 			return (field->buffers[0].length <= field->cols);
284 		} else {
285 			return (field->row_count <= (field->rows
286 						     + field->nrows));
287 		}
288 	}
289 }
290 
291 /*
292  * Set the form's current field to the first valid field on the page.
293  * Assume the fields have been sorted and stitched.
294  */
295 int
296 _formi_pos_first_field(FORM *form)
297 {
298 	FIELD *cur;
299 	int old_page;
300 
301 	old_page = form->page;
302 
303 	  /* scan forward for an active page....*/
304 	while (form->page_starts[form->page].in_use == 0) {
305 		form->page++;
306 		if (form->page > form->max_page) {
307 			form->page = old_page;
308 			return E_REQUEST_DENIED;
309 		}
310 	}
311 
312 	  /* then scan for a field we can use */
313 	cur = form->fields[form->page_starts[form->page].first];
314 	while ((cur->opts & (O_VISIBLE | O_ACTIVE))
315 	       != (O_VISIBLE | O_ACTIVE)) {
316 		cur = CIRCLEQ_NEXT(cur, glue);
317 		if (cur == (void *) &form->sorted_fields) {
318 			form->page = old_page;
319 			return E_REQUEST_DENIED;
320 		}
321 	}
322 
323 	form->cur_field = cur->index;
324 	return E_OK;
325 }
326 
327 /*
328  * Set the field to the next active and visible field, the fields are
329  * traversed in index order in the direction given.  If the parameter
330  * use_sorted is TRUE then the sorted field list will be traversed instead
331  * of using the field index.
332  */
333 int
334 _formi_pos_new_field(FORM *form, unsigned direction, unsigned use_sorted)
335 {
336 	FIELD *cur;
337 	int i;
338 
339 	i = form->cur_field;
340 	cur = form->fields[i];
341 
342 	do {
343 		if (direction == _FORMI_FORWARD) {
344 			if (use_sorted == TRUE) {
345 				if ((form->wrap == FALSE) &&
346 				    (cur == CIRCLEQ_LAST(&form->sorted_fields)))
347 					return E_REQUEST_DENIED;
348 				cur = CIRCLEQ_NEXT(cur, glue);
349 				i = cur->index;
350 			} else {
351 				if ((form->wrap == FALSE) &&
352 				    ((i + 1) >= form->field_count))
353 					return E_REQUEST_DENIED;
354 				i++;
355 				if (i >= form->field_count)
356 					i = 0;
357 			}
358 		} else {
359 			if (use_sorted == TRUE) {
360 				if ((form->wrap == FALSE) &&
361 				    (cur == CIRCLEQ_FIRST(&form->sorted_fields)))
362 					return E_REQUEST_DENIED;
363 				cur = CIRCLEQ_PREV(cur, glue);
364 				i = cur->index;
365 			} else {
366 				if ((form->wrap == FALSE) && (i <= 0))
367 					return E_REQUEST_DENIED;
368 				i--;
369 				if (i < 0)
370 					i = form->field_count - 1;
371 			}
372 		}
373 
374 		if ((form->fields[i]->opts & (O_VISIBLE | O_ACTIVE))
375 			== (O_VISIBLE | O_ACTIVE)) {
376 			form->cur_field = i;
377 			return E_OK;
378 		}
379 	}
380 	while (i != form->cur_field);
381 
382 	return E_REQUEST_DENIED;
383 }
384 
385 /*
386  * Find the line in a field that the cursor is currently on.
387  */
388 static int
389 find_cur_line(FIELD *cur, unsigned pos)
390 {
391 	unsigned row;
392 
393 	  /* if there is only one row then that must be it */
394 	if (cur->row_count == 1)
395 		return 0;
396 
397 	  /* first check if pos is at the end of the string, if this
398 	   * is true then just return the last row since the pos may
399 	   * not have been added to the lines array yet.
400 	   */
401 	if (pos == (cur->buffers[0].length - 1))
402 		return (cur->row_count - 1);
403 
404 	for (row = 0; row < cur->row_count; row++) {
405 		if ((pos >= cur->lines[row].start)
406 		    && (pos <= cur->lines[row].end))
407 			return row;
408 	}
409 
410 #ifdef DEBUG
411 	  /* barf if we get here, this should not be possible */
412 	assert((row != row));
413 #endif
414 	return 0;
415 }
416 
417 
418 /*
419  * Word wrap the contents of the field's buffer 0 if this is allowed.
420  * If the wrap is successful, that is, the row count nor the buffer
421  * size is exceeded then the function will return E_OK, otherwise it
422  * will return E_REQUEST_DENIED.
423  */
424 int
425 _formi_wrap_field(FIELD *field, unsigned int loc)
426 {
427 	char *str;
428 	int width, row, start_row;
429 	unsigned int pos;
430 
431 	str = field->buffers[0].string;
432 
433 	if ((field->opts & O_STATIC) == O_STATIC) {
434 		if ((field->rows + field->nrows) == 1) {
435 			return E_OK; /* cannot wrap a single line */
436 		}
437 		width = field->cols;
438 	} else {
439 		  /* if we are limited to one line then don't try to wrap */
440 		if ((field->drows + field->nrows) == 1) {
441 			return E_OK;
442 		}
443 
444 		  /*
445 		   * hueristic - if a dynamic field has more than one line
446 		   * on the screen then the field grows rows, otherwise
447 		   * it grows columns, effectively a single line field.
448 		   * This is documented AT&T behaviour.
449 		   */
450 		if (field->rows > 1) {
451 			width = field->cols;
452 		} else {
453 			return E_OK;
454 		}
455 	}
456 
457 	start_row = find_cur_line(field, loc);
458 
459 	  /* if we are not at the top of the field then back up one
460 	   * row because we may be able to merge the current row into
461 	   * the one above.
462 	   */
463 	if (start_row > 0)
464 		start_row--;
465 
466 	for (row = start_row; row < field->row_count; row++) {
467 	  AGAIN:
468 		pos = field->lines[row].end;
469 		if (field->lines[row].length < width) {
470 			  /* line may be too short, try joining some lines */
471 
472 			if ((((int) field->row_count) - 1) == row) {
473 				/* if this is the last row then don't
474 				 * wrap
475 				 */
476 				continue;
477 			}
478 
479 			if (_formi_join_line(field, (unsigned int) pos,
480 					     JOIN_NEXT_NW) == E_OK) {
481 				goto AGAIN;
482 			} else
483 				break;
484 		} else {
485 			  /* line is too long, split it - maybe */
486 
487 			  /* first check if we have not run out of room */
488 			if ((field->opts & O_STATIC) == O_STATIC) {
489 				/* check static field */
490 				if ((field->rows + field->nrows - 1) == row)
491 					return E_REQUEST_DENIED;
492 			} else {
493 				/* check dynamic field */
494 				if ((field->max != 0)
495 				    && ((field->max - 1) == row))
496 					return E_REQUEST_DENIED;
497 			}
498 
499 			  /*
500 			   * split on first whitespace before current word
501 			   * if the line has tabs we need to work out where
502 			   * the field border lies when the tabs are expanded.
503 			   */
504 			if (field->lines[row].tabs == NULL) {
505 				pos = width + field->lines[row].start - 1;
506 				if (pos >= field->buffers[0].length)
507 					pos = field->buffers[0].length - 1;
508 			} else {
509 				pos = tab_fit_len(field, (unsigned) row,
510 						  field->cols);
511 			}
512 
513 
514 			if ((!isblank(str[pos])) &&
515 			    ((field->opts & O_WRAP) == O_WRAP)) {
516 				if (!isblank(str[pos - 1]))
517 					pos = find_sow(str,
518 						       (unsigned int) pos);
519 				/*
520 				 * If we cannot split the line then return
521 				 * NO_ROOM so the driver can tell that it
522 				 * should not autoskip (if that is enabled)
523 				 */
524 				if ((pos == 0) || (!isblank(str[pos - 1]))
525 				    || ((pos <= field->lines[row].start)
526 					&& (field->buffers[0].length
527 					    >= (width - 1
528 						+ field->lines[row].start)))) {
529 					return E_NO_ROOM;
530 				}
531 			}
532 
533 			  /* if we are at the end of the string and it has
534 			   * a trailing blank, don't wrap the blank.
535 			   */
536 			if ((pos == field->buffers[0].length - 1) &&
537 			    (isblank(str[pos])) &&
538 			    field->lines[row].length <= field->cols)
539 				continue;
540 
541 			  /*
542 			   * otherwise, if we are still sitting on a
543 			   * blank but not at the end of the line
544 			   * move forward one char so the blank
545 			   * is on the line boundary.
546 			   */
547 			if ((isblank(str[pos])) &&
548 			    (pos != field->buffers[0].length - 1))
549 				pos++;
550 
551 			if (split_line(field, pos) != E_OK) {
552 				return E_REQUEST_DENIED;
553 			}
554 		}
555 	}
556 
557 	return E_OK;
558 }
559 
560 /*
561  * Join the two lines that surround the location pos, the type
562  * variable indicates the direction of the join, JOIN_NEXT will join
563  * the next line to the current line, JOIN_PREV will join the current
564  * line to the previous line, the new lines will be wrapped unless the
565  * _NW versions of the directions are used.  Returns E_OK if the join
566  * was successful or E_REQUEST_DENIED if the join cannot happen.
567  */
568 static int
569 _formi_join_line(FIELD *field, unsigned int pos, int direction)
570 {
571 	unsigned int row, i;
572 	int old_alloced, old_row_count;
573 	struct _formi_field_lines *saved;
574 #ifdef DEBUG
575 	int dbg_ok = FALSE;
576 
577 	if (_formi_create_dbg_file() == E_OK) {
578 		dbg_ok = TRUE;
579 	}
580 #endif
581 
582 	if ((saved = (struct _formi_field_lines *)
583 	     malloc(field->lines_alloced * sizeof(struct _formi_field_lines)))
584 	    == NULL)
585 		return E_REQUEST_DENIED;
586 
587 	bcopy(field->lines, saved,
588 	      field->row_count * sizeof(struct _formi_field_lines));
589 	old_alloced = field->lines_alloced;
590 	old_row_count = field->row_count;
591 
592 	row = find_cur_line(field, pos);
593 
594 #ifdef DEBUG
595 	if (dbg_ok == TRUE) {
596 		fprintf(dbg, "join_line: working on row %d, row_count = %d\n",
597 			row, field->row_count);
598 	}
599 #endif
600 
601 	if ((direction == JOIN_NEXT) || (direction == JOIN_NEXT_NW)) {
602 		  /* see if there is another line following... */
603 		if (row == (field->row_count - 1)) {
604 			free(saved);
605 			return E_REQUEST_DENIED;
606 		}
607 
608 #ifdef DEBUG
609 		if (dbg_ok == TRUE) {
610 			fprintf(dbg,
611 			"join_line: join_next before end = %d, length = %d",
612 				field->lines[row].end,
613 				field->lines[row].length);
614 			fprintf(dbg,
615 				" :: next row end = %d, length = %d\n",
616 				field->lines[row + 1].end,
617 				field->lines[row + 1].length);
618 		}
619 #endif
620 
621 		field->lines[row].end = field->lines[row + 1].end;
622 		field->lines[row].length =
623 			_formi_tab_expanded_length(field->buffers[0].string,
624 					    field->lines[row].start,
625 					    field->lines[row].end);
626 		_formi_calculate_tabs(field, row);
627 
628 		  /* shift all the remaining lines up.... */
629 		for (i = row + 2; i < field->row_count; i++)
630 			field->lines[i - 1] = field->lines[i];
631 	} else {
632 		if ((pos == 0) || (row == 0)) {
633 			free(saved);
634 			return E_REQUEST_DENIED;
635 		}
636 
637 #ifdef DEBUG
638 		if (dbg_ok == TRUE) {
639 			fprintf(dbg,
640 			"join_line: join_prev before end = %d, length = %d",
641 				field->lines[row].end,
642 				field->lines[row].length);
643 			fprintf(dbg,
644 				" :: prev row end = %d, length = %d\n",
645 				field->lines[row - 1].end,
646 				field->lines[row - 1].length);
647 		}
648 #endif
649 
650 		field->lines[row - 1].end = field->lines[row].end;
651 		field->lines[row - 1].length =
652 			_formi_tab_expanded_length(field->buffers[0].string,
653 					    field->lines[row - 1].start,
654 					    field->lines[row].end);
655 		  /* shift all the remaining lines up */
656 		for (i = row + 1; i < field->row_count; i++)
657 			field->lines[i - 1] = field->lines[i];
658 	}
659 
660 #ifdef DEBUG
661 	if (dbg_ok == TRUE) {
662 		fprintf(dbg,
663 			"join_line: exit end = %d, length = %d\n",
664 			field->lines[row].end, field->lines[row].length);
665 	}
666 #endif
667 
668 	field->row_count--;
669 
670 	  /* wrap the field if required, if this fails undo the change */
671 	if ((direction == JOIN_NEXT) || (direction == JOIN_PREV)) {
672 		if (_formi_wrap_field(field, (unsigned int) pos) != E_OK) {
673 			free(field->lines);
674 			field->lines = saved;
675 			field->lines_alloced = old_alloced;
676 			field->row_count = old_row_count;
677 			for (i = 0; i < field->row_count; i++)
678 				_formi_calculate_tabs(field, i);
679 			return E_REQUEST_DENIED;
680 		}
681 	}
682 
683 	free(saved);
684 	return E_OK;
685 }
686 
687 /*
688  * Split the line at the given position, if possible
689  */
690 static int
691 split_line(FIELD *field, unsigned pos)
692 {
693 	struct _formi_field_lines *new_lines;
694 	unsigned int row, i;
695 #ifdef DEBUG
696 	short dbg_ok = FALSE;
697 #endif
698 
699 	if (pos == 0)
700 		return E_REQUEST_DENIED;
701 
702 #ifdef DEBUG
703 	if (_formi_create_dbg_file() == E_OK) {
704 		fprintf(dbg, "split_line: splitting line at %d\n", pos);
705 		dbg_ok = TRUE;
706 	}
707 #endif
708 
709 	if ((field->row_count + 1) > field->lines_alloced) {
710 		if ((new_lines = (struct _formi_field_lines *)
711 		     realloc(field->lines, (field->row_count + 1)
712 			     * sizeof(struct _formi_field_lines))) == NULL)
713 			return E_SYSTEM_ERROR;
714 		field->lines = new_lines;
715 		field->lines_alloced++;
716 	}
717 
718 	row = find_cur_line(field, pos);
719 #ifdef DEBUG
720 	if (dbg_ok == TRUE) {
721 		fprintf(dbg,
722 	"split_line: enter: lines[%d].end = %d, lines[%d].length = %d\n",
723 			row, field->lines[row].end, row,
724 			field->lines[row].length);
725 	}
726 
727 	assert(((field->lines[row].end < INT_MAX) &&
728 		(field->lines[row].length < INT_MAX) &&
729 		(field->lines[row].length > 0)));
730 
731 #endif
732 
733 	  /* if asked to split right where the line already starts then
734 	   * just return - nothing to do.
735 	   */
736 	if (field->lines[row].start == pos)
737 		return E_OK;
738 
739 	for (i = field->row_count - 1; i > row; i--) {
740 		field->lines[i + 1] = field->lines[i];
741 	}
742 
743 	field->lines[row + 1].end = field->lines[row].end;
744 	field->lines[row].end = pos - 1;
745 	field->lines[row].length =
746 		_formi_tab_expanded_length(field->buffers[0].string,
747 				    field->lines[row].start,
748 				    field->lines[row].end);
749 	_formi_calculate_tabs(field, row);
750 	field->lines[row + 1].start = pos;
751 	field->lines[row + 1].length =
752 		_formi_tab_expanded_length(field->buffers[0].string,
753 				    field->lines[row + 1].start,
754 				    field->lines[row + 1].end);
755 	field->lines[row + 1].tabs = NULL;
756 	_formi_calculate_tabs(field, row + 1);
757 
758 #ifdef DEBUG
759 	assert(((field->lines[row + 1].end < INT_MAX) &&
760 		(field->lines[row].end < INT_MAX) &&
761 		(field->lines[row].length < INT_MAX) &&
762 		(field->lines[row + 1].start < INT_MAX) &&
763 		(field->lines[row + 1].length < INT_MAX) &&
764 		(field->lines[row].length > 0) &&
765 		(field->lines[row + 1].length > 0)));
766 
767 	if (dbg_ok == TRUE) {
768 		fprintf(dbg,
769 	"split_line: exit: lines[%d].end = %d, lines[%d].length = %d, ",
770 			row, field->lines[row].end, row,
771 			field->lines[row].length);
772 		fprintf(dbg, "lines[%d].start = %d, lines[%d].end = %d, ",
773 			row + 1, field->lines[row + 1].start, row + 1,
774 			field->lines[row + 1].end);
775 		fprintf(dbg, "lines[%d].length = %d, row_count = %d\n",
776 			row + 1, field->lines[row + 1].length,
777 			field->row_count + 1);
778 	}
779 #endif
780 
781 	field->row_count++;
782 
783 #ifdef DEBUG
784 	if (dbg_ok == TRUE) {
785 		bump_lines(field, 0, 0, FALSE); /* will report line data for us */
786 	}
787 #endif
788 
789 	return E_OK;
790 }
791 
792 /*
793  * skip the blanks in the given string, start at the index start and
794  * continue forward until either the end of the string or a non-blank
795  * character is found.  Return the index of either the end of the string or
796  * the first non-blank character.
797  */
798 unsigned
799 _formi_skip_blanks(char *string, unsigned int start)
800 {
801 	unsigned int i;
802 
803 	i = start;
804 
805 	while ((string[i] != '\0') && isblank(string[i]))
806 		i++;
807 
808 	return i;
809 }
810 
811 /*
812  * Return the index of the top left most field of the two given fields.
813  */
814 static int
815 _formi_top_left(FORM *form, int a, int b)
816 {
817 	  /* lower row numbers always win here.... */
818 	if (form->fields[a]->form_row < form->fields[b]->form_row)
819 		return a;
820 
821 	if (form->fields[a]->form_row > form->fields[b]->form_row)
822 		return b;
823 
824 	  /* rows must be equal, check columns */
825 	if (form->fields[a]->form_col < form->fields[b]->form_col)
826 		return a;
827 
828 	if (form->fields[a]->form_col > form->fields[b]->form_col)
829 		return b;
830 
831 	  /* if we get here fields must be in exactly the same place, punt */
832 	return a;
833 }
834 
835 /*
836  * Return the index to the field that is the bottom-right-most of the
837  * two given fields.
838  */
839 static int
840 _formi_bottom_right(FORM *form, int a, int b)
841 {
842 	  /* check the rows first, biggest row wins */
843 	if (form->fields[a]->form_row > form->fields[b]->form_row)
844 		return a;
845 	if (form->fields[a]->form_row < form->fields[b]->form_row)
846 		return b;
847 
848 	  /* rows must be equal, check cols, biggest wins */
849 	if (form->fields[a]->form_col > form->fields[b]->form_col)
850 		return a;
851 	if (form->fields[a]->form_col < form->fields[b]->form_col)
852 		return b;
853 
854 	  /* fields in the same place, punt */
855 	return a;
856 }
857 
858 /*
859  * Find the end of the current word in the string str, starting at
860  * offset - the end includes any trailing whitespace.  If the end of
861  * the string is found before a new word then just return the offset
862  * to the end of the string.
863  */
864 static int
865 find_eow(char *str, unsigned int offset)
866 {
867 	int start;
868 
869 	start = offset;
870 	  /* first skip any non-whitespace */
871 	while ((str[start] != '\0') && !isblank(str[start]))
872 		start++;
873 
874 	  /* see if we hit the end of the string */
875 	if (str[start] == '\0')
876 		return start;
877 
878 	  /* otherwise skip the whitespace.... */
879 	while ((str[start] != '\0') && isblank(str[start]))
880 		start++;
881 
882 	return start;
883 }
884 
885 /*
886  * Find the beginning of the current word in the string str, starting
887  * at offset.
888  */
889 static int
890 find_sow(char *str, unsigned int offset)
891 {
892 	int start;
893 
894 	start = offset;
895 
896 	if (start > 0) {
897 		if (isblank(str[start]) || isblank(str[start - 1])) {
898 			if (isblank(str[start - 1]))
899 				start--;
900 			  /* skip the whitespace.... */
901 			while ((start >= 0) && isblank(str[start]))
902 				start--;
903 		}
904 	}
905 
906 	  /* see if we hit the start of the string */
907 	if (start < 0)
908 		return 0;
909 
910 	  /* now skip any non-whitespace */
911 	while ((start >= 0) && !isblank(str[start]))
912 		start--;
913 
914 	if (start > 0)
915 		start++; /* last loop has us pointing at a space, adjust */
916 
917 	if (start < 0)
918 		start = 0;
919 
920 	return start;
921 }
922 
923 /*
924  * Scroll the field forward the given number of lines.
925  */
926 static void
927 _formi_scroll_fwd(FIELD *field, unsigned int amt)
928 {
929 	  /* check if we have lines to scroll */
930 	if (field->row_count < (field->start_line + field->rows))
931 		return;
932 
933 	field->start_line += min(amt,
934 				 field->row_count - field->start_line
935 				 - field->rows);
936 }
937 
938 /*
939  * Scroll the field backward the given number of lines.
940  */
941 static void
942 _formi_scroll_back(FIELD *field, unsigned int amt)
943 {
944 	if (field->start_line == 0)
945 		return;
946 
947 	field->start_line -= min(field->start_line, amt);
948 }
949 
950 /*
951  * Scroll the field forward the given number of characters.
952  */
953 void
954 _formi_hscroll_fwd(FIELD *field, int unsigned amt)
955 {
956 	unsigned int row, end, scroll_amt, expanded;
957 	_formi_tab_t *ts;
958 
959 	row = field->start_line + field->cursor_ypos;
960 
961 	if ((field->lines[row].tabs == NULL)
962 	    || (field->lines[row].tabs->in_use == FALSE)) {
963 		  /* if the line has no tabs things are easy... */
964 		end =  field->start_char + field->cols + amt - 1;
965 		scroll_amt = amt;
966 		if (end > field->lines[row].end) {
967 			end = field->lines[row].end;
968 			scroll_amt = end - field->start_char - field->cols + 1;
969 		}
970 	} else {
971 		  /*
972 		   * If there are tabs we need to add on the scroll amount,
973 		   * find the last char position that will fit into
974 		   * the field and finally fix up the start_char.  This
975 		   * is a lot of work but handling the case where there
976 		   * are not enough chars to scroll by amt is difficult.
977 		   */
978 		end = field->start_char + field->row_xpos + amt;
979 		if (end >= field->buffers[0].length)
980 			end = field->buffers[0].length - 1;
981 		else {
982 			expanded = _formi_tab_expanded_length(
983 				field->buffers[0].string,
984 				field->start_char + amt,
985 				field->start_char + field->row_xpos + amt);
986 			ts = field->lines[0].tabs;
987 			  /* skip tabs to the lhs of our starting point */
988 			while ((ts != NULL) && (ts->in_use == TRUE)
989 			       && (ts->pos < end))
990 				ts = ts->fwd;
991 
992 			while ((expanded <= field->cols)
993 			       && (end < field->buffers[0].length)) {
994 				if (field->buffers[0].string[end] == '\t') {
995 #ifdef DEBUG
996 					assert((ts != NULL)
997 					       && (ts->in_use == TRUE));
998 #endif
999 					if (ts->pos == end) {
1000 						if ((expanded + ts->size)
1001 						    > field->cols)
1002 							break;
1003 						expanded += ts->size;
1004 						ts = ts->fwd;
1005 					}
1006 #ifdef DEBUG
1007 					else
1008 						assert(ts->pos == end);
1009 #endif
1010 				} else
1011 					expanded++;
1012 				end++;
1013 			}
1014 		}
1015 
1016 		scroll_amt = tab_fit_window(field, end, field->cols);
1017 		if (scroll_amt < field->start_char)
1018 			scroll_amt = 1;
1019 		else
1020 			scroll_amt -= field->start_char;
1021 
1022 		scroll_amt = min(scroll_amt, amt);
1023 	}
1024 
1025 	field->start_char += scroll_amt;
1026 	field->cursor_xpos =
1027 		_formi_tab_expanded_length(field->buffers[0].string,
1028 					   field->start_char,
1029 					   field->row_xpos
1030 					   + field->start_char) - 1;
1031 
1032 }
1033 
1034 /*
1035  * Scroll the field backward the given number of characters.
1036  */
1037 void
1038 _formi_hscroll_back(FIELD *field, unsigned int amt)
1039 {
1040 	field->start_char -= min(field->start_char, amt);
1041 	field->cursor_xpos =
1042 		_formi_tab_expanded_length(field->buffers[0].string,
1043 					   field->start_char,
1044 					   field->row_xpos
1045 					   + field->start_char) - 1;
1046 	if (field->cursor_xpos >= field->cols) {
1047 		field->row_xpos = 0;
1048 		field->cursor_xpos = 0;
1049 	}
1050 }
1051 
1052 /*
1053  * Find the different pages in the form fields and assign the form
1054  * page_starts array with the information to find them.
1055  */
1056 int
1057 _formi_find_pages(FORM *form)
1058 {
1059 	int i, cur_page = 0;
1060 
1061 	if ((form->page_starts = (_FORMI_PAGE_START *)
1062 	     malloc((form->max_page + 1) * sizeof(_FORMI_PAGE_START))) == NULL)
1063 		return E_SYSTEM_ERROR;
1064 
1065 	  /* initialise the page starts array */
1066 	memset(form->page_starts, 0,
1067 	       (form->max_page + 1) * sizeof(_FORMI_PAGE_START));
1068 
1069 	for (i =0; i < form->field_count; i++) {
1070 		if (form->fields[i]->page_break == 1)
1071 			cur_page++;
1072 		if (form->page_starts[cur_page].in_use == 0) {
1073 			form->page_starts[cur_page].in_use = 1;
1074 			form->page_starts[cur_page].first = i;
1075 			form->page_starts[cur_page].last = i;
1076 			form->page_starts[cur_page].top_left = i;
1077 			form->page_starts[cur_page].bottom_right = i;
1078 		} else {
1079 			form->page_starts[cur_page].last = i;
1080 			form->page_starts[cur_page].top_left =
1081 				_formi_top_left(form,
1082 						form->page_starts[cur_page].top_left,
1083 						i);
1084 			form->page_starts[cur_page].bottom_right =
1085 				_formi_bottom_right(form,
1086 						    form->page_starts[cur_page].bottom_right,
1087 						    i);
1088 		}
1089 	}
1090 
1091 	return E_OK;
1092 }
1093 
1094 /*
1095  * Completely redraw the field of the given form.
1096  */
1097 void
1098 _formi_redraw_field(FORM *form, int field)
1099 {
1100 	unsigned int pre, post, flen, slen, i, row, start;
1101 	unsigned int last_row, tab, cpos, len;
1102 	char *str, c;
1103 	FIELD *cur;
1104 #ifdef DEBUG
1105 	char buffer[100];
1106 #endif
1107 
1108 	cur = form->fields[field];
1109 	str = cur->buffers[0].string;
1110 	flen = cur->cols;
1111 	slen = 0;
1112 	start = 0;
1113 
1114 	if ((cur->row_count - cur->start_line) < cur->rows)
1115 		last_row = cur->row_count;
1116 	else
1117 		last_row = cur->start_line + cur->rows;
1118 
1119 	for (row = cur->start_line; row < last_row; row++) {
1120 		wmove(form->scrwin,
1121 		      (int) (cur->form_row + row - cur->start_line),
1122 		      (int) cur->form_col);
1123 		start = cur->lines[row].start;
1124 		if ((cur->rows + cur->nrows) == 1) {
1125 			if ((cur->start_char + cur->cols)
1126 			    >= cur->buffers[0].length)
1127 				len = cur->buffers[0].length;
1128 			else
1129 				len = cur->cols + cur->start_char;
1130 			slen = _formi_tab_expanded_length(
1131 				cur->buffers[0].string, cur->start_char, len);
1132 			if (slen > cur->cols)
1133 				slen = cur->cols;
1134 			slen += cur->start_char;
1135 		} else
1136 			slen = cur->lines[row].length;
1137 
1138 		if ((cur->opts & O_STATIC) == O_STATIC) {
1139 			switch (cur->justification) {
1140 			case JUSTIFY_RIGHT:
1141 				post = 0;
1142 				if (flen < slen)
1143 					pre = 0;
1144 				else
1145 					pre = flen - slen;
1146 				break;
1147 
1148 			case JUSTIFY_CENTER:
1149 				if (flen < slen) {
1150 					pre = 0;
1151 					post = 0;
1152 				} else {
1153 					pre = flen - slen;
1154 					post = pre = pre / 2;
1155 					  /* get padding right if
1156                                              centring is not even */
1157 					if ((post + pre + slen) < flen)
1158 						post++;
1159 				}
1160 				break;
1161 
1162 			case NO_JUSTIFICATION:
1163 			case JUSTIFY_LEFT:
1164 			default:
1165 				pre = 0;
1166 				if (flen <= slen)
1167 					post = 0;
1168 				else {
1169 					post = flen - slen;
1170 					if (post > flen)
1171 						post = flen;
1172 				}
1173 				break;
1174 			}
1175 		} else {
1176 			  /* dynamic fields are not justified */
1177 			pre = 0;
1178 			if (flen <= slen)
1179 				post = 0;
1180 			else {
1181 				post = flen - slen;
1182 				if (post > flen)
1183 					post = flen;
1184 			}
1185 
1186 			  /* but they do scroll.... */
1187 
1188 			if (pre > cur->start_char - start)
1189 				pre = pre - cur->start_char + start;
1190 			else
1191 				pre = 0;
1192 
1193 			if (slen > cur->start_char) {
1194 				slen -= cur->start_char;
1195 				if (slen > flen)
1196 					post = 0;
1197 				else
1198 					post = flen - slen;
1199 
1200 				if (post > flen)
1201 					post = flen;
1202 			} else {
1203 				slen = 0;
1204 				post = flen - pre;
1205 			}
1206 		}
1207 
1208 		if (form->cur_field == field)
1209 			wattrset(form->scrwin, cur->fore);
1210 		else
1211 			wattrset(form->scrwin, cur->back);
1212 
1213 #ifdef DEBUG
1214 		if (_formi_create_dbg_file() == E_OK) {
1215 			fprintf(dbg,
1216   "redraw_field: start=%d, pre=%d, slen=%d, flen=%d, post=%d, start_char=%d\n",
1217 				start, pre, slen, flen, post, cur->start_char);
1218 			if (str != NULL) {
1219 				strncpy(buffer,
1220 					&str[cur->start_char
1221 					    + cur->lines[row].start], flen);
1222 			} else {
1223 				strcpy(buffer, "(null)");
1224 			}
1225 			buffer[flen] = '\0';
1226 			fprintf(dbg, "redraw_field: %s\n", buffer);
1227 		}
1228 #endif
1229 
1230 		for (i = start + cur->start_char; i < pre; i++)
1231 			waddch(form->scrwin, cur->pad);
1232 
1233 #ifdef DEBUG
1234 		fprintf(dbg, "redraw_field: will add %d chars\n",
1235 			min(slen, flen));
1236 #endif
1237 		str = &cur->buffers[0].string[cur->start_char
1238 					     + cur->lines[row].start];
1239 
1240 		for (i = 0, cpos = cur->start_char; i < min(slen, flen);
1241 		     i++, str++, cpos++)
1242 		{
1243 			c = *str;
1244 			tab = 0; /* just to shut gcc up */
1245 #ifdef DEBUG
1246 			fprintf(dbg, "adding char str[%d]=%c\n",
1247 				cpos + cur->start_char + cur->lines[row].start,
1248 				c);
1249 #endif
1250 			if (((cur->opts & O_PUBLIC) != O_PUBLIC)) {
1251 				if (c == '\t')
1252 					tab = add_tab(form, cur, row,
1253 						      cpos, cur->pad);
1254 				else
1255 					waddch(form->scrwin, cur->pad);
1256 			} else if ((cur->opts & O_VISIBLE) == O_VISIBLE) {
1257 				if (c == '\t')
1258 					tab = add_tab(form, cur, row, cpos,
1259 						      ' ');
1260 				else
1261 					waddch(form->scrwin, c);
1262 			} else {
1263 				if (c == '\t')
1264 					tab = add_tab(form, cur, row, cpos,
1265 						      ' ');
1266 				else
1267 					waddch(form->scrwin, ' ');
1268 			}
1269 
1270 			  /*
1271 			   * If we have had a tab then skip forward
1272 			   * the requisite number of chars to keep
1273 			   * things in sync.
1274 			   */
1275 			if (c == '\t')
1276 				i += tab - 1;
1277 		}
1278 
1279 		for (i = 0; i < post; i++)
1280 			waddch(form->scrwin, cur->pad);
1281 	}
1282 
1283 	for (row = cur->row_count - cur->start_line; row < cur->rows; row++) {
1284 		wmove(form->scrwin, (int) (cur->form_row + row),
1285 		      (int) cur->form_col);
1286 
1287 		if (form->cur_field == field)
1288 			wattrset(form->scrwin, cur->fore);
1289 		else
1290 			wattrset(form->scrwin, cur->back);
1291 
1292 		for (i = 0; i < cur->cols; i++) {
1293 			waddch(form->scrwin, cur->pad);
1294 		}
1295 	}
1296 
1297 	wattrset(form->scrwin, cur->back);
1298 	return;
1299 }
1300 
1301 /*
1302  * Add the correct number of the given character to simulate a tab
1303  * in the field.
1304  */
1305 static int
1306 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c)
1307 {
1308 	int j;
1309 	_formi_tab_t *ts = field->lines[row].tabs;
1310 
1311 	while ((ts != NULL) && (ts->pos != i))
1312 		ts = ts->fwd;
1313 
1314 #ifdef DEBUG
1315 	assert(ts != NULL);
1316 #endif
1317 
1318 	for (j = 0; j < ts->size; j++)
1319 		waddch(form->scrwin, c);
1320 
1321 	return ts->size;
1322 }
1323 
1324 
1325 /*
1326  * Display the fields attached to the form that are on the current page
1327  * on the screen.
1328  *
1329  */
1330 int
1331 _formi_draw_page(FORM *form)
1332 {
1333 	int i;
1334 
1335 	if (form->page_starts[form->page].in_use == 0)
1336 		return E_BAD_ARGUMENT;
1337 
1338 	wclear(form->scrwin);
1339 
1340 	for (i = form->page_starts[form->page].first;
1341 	     i <= form->page_starts[form->page].last; i++)
1342 		_formi_redraw_field(form, i);
1343 
1344 	return E_OK;
1345 }
1346 
1347 /*
1348  * Add the character c at the position pos in buffer 0 of the given field
1349  */
1350 int
1351 _formi_add_char(FIELD *field, unsigned int pos, char c)
1352 {
1353 	char *new, old_c;
1354 	unsigned int new_size;
1355 	int status;
1356 
1357 	  /*
1358 	   * If buffer has not had a string before, set it to a blank
1359 	   * string.  Everything should flow from there....
1360 	   */
1361 	if (field->buffers[0].string == NULL) {
1362 		set_field_buffer(field, 0, "");
1363 	}
1364 
1365 	if (_formi_validate_char(field, c) != E_OK) {
1366 #ifdef DEBUG
1367 		fprintf(dbg, "add_char: char %c failed char validation\n", c);
1368 #endif
1369 		return E_INVALID_FIELD;
1370 	}
1371 
1372 	if ((c == '\t') && (field->cols <= 8)) {
1373 #ifdef DEBUG
1374 		fprintf(dbg, "add_char: field too small for a tab\n");
1375 #endif
1376 		return E_NO_ROOM;
1377 	}
1378 
1379 #ifdef DEBUG
1380 	fprintf(dbg, "add_char: pos=%d, char=%c\n", pos, c);
1381 	fprintf(dbg, "add_char enter: xpos=%d, row_pos=%d, start=%d\n",
1382 		field->cursor_xpos, field->row_xpos, field->start_char);
1383 	fprintf(dbg, "add_char enter: length=%d(%d), allocated=%d\n",
1384 		field->buffers[0].length, strlen(field->buffers[0].string),
1385 		field->buffers[0].allocated);
1386 	fprintf(dbg, "add_char enter: %s\n", field->buffers[0].string);
1387 	fprintf(dbg, "add_char enter: buf0_status=%d\n", field->buf0_status);
1388 #endif
1389 	if (((field->opts & O_BLANK) == O_BLANK) &&
1390 	    (field->buf0_status == FALSE) &&
1391 	    ((field->row_xpos + field->start_char) == 0)) {
1392 		field->buffers[0].length = 0;
1393 		field->buffers[0].string[0] = '\0';
1394 		pos = 0;
1395 		field->start_char = 0;
1396 		field->start_line = 0;
1397 		field->row_count = 1;
1398 		field->row_xpos = 0;
1399 		field->cursor_ypos = 0;
1400 		field->lines[0].start = 0;
1401 		field->lines[0].end = 0;
1402 		field->lines[0].length = 0;
1403 		_formi_init_field_xpos(field);
1404 	}
1405 
1406 
1407 	if ((field->overlay == 0)
1408 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1409 		  /* first check if the field can have more chars...*/
1410 		if (check_field_size(field) == FALSE)
1411 			return E_REQUEST_DENIED;
1412 
1413 		if (field->buffers[0].length + 1
1414 		    >= field->buffers[0].allocated) {
1415 			new_size = field->buffers[0].allocated + 64
1416 				- (field->buffers[0].allocated % 64);
1417 			if ((new = (char *) realloc(field->buffers[0].string,
1418 						    new_size )) == NULL)
1419 				return E_SYSTEM_ERROR;
1420 			field->buffers[0].allocated = new_size;
1421 			field->buffers[0].string = new;
1422 		}
1423 	}
1424 
1425 	if ((field->overlay == 0) && (field->buffers[0].length > pos)) {
1426 		bcopy(&field->buffers[0].string[pos],
1427 		      &field->buffers[0].string[pos + 1],
1428 		      field->buffers[0].length - pos + 1);
1429 	}
1430 
1431 	old_c = field->buffers[0].string[pos];
1432 	field->buffers[0].string[pos] = c;
1433 	if (pos >= field->buffers[0].length) {
1434 		  /* make sure the string is terminated if we are at the
1435 		   * end of the string, the terminator would be missing
1436 		   * if we are are at the end of the field.
1437 		   */
1438 		field->buffers[0].string[pos + 1] = '\0';
1439 	}
1440 
1441 	  /* only increment the length if we are inserting characters
1442 	   * OR if we are at the end of the field in overlay mode.
1443 	   */
1444 	if ((field->overlay == 0)
1445 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1446 		field->buffers[0].length++;
1447 		bump_lines(field, (int) pos, 1, TRUE);
1448 	} else if (field->overlay == 1)
1449 		bump_lines(field, (int) pos, 0, TRUE);
1450 
1451 	new_size = find_cur_line(field, pos);
1452 	_formi_calculate_tabs(field, new_size);
1453 
1454 	  /* wrap the field, if needed */
1455 	status = _formi_wrap_field(field, pos);
1456 
1457 	  /* just in case the row we are on wrapped */
1458 	new_size = find_cur_line(field, pos);
1459 
1460 	  /*
1461 	   * check the wrap worked or that we have not exceeded the
1462 	   * max field size - this can happen if the field is re-wrapped
1463 	   * and the row count is increased past the set limit.
1464 	   */
1465 	if ((status != E_OK) || (check_field_size(field) == FALSE)) {
1466 		if ((field->overlay == 0)
1467 		    || ((field->overlay == 1)
1468 			&& (pos >= field->buffers[0].length))) {
1469 			  /*
1470 			   * wrap failed for some reason, back out the
1471 			   * char insert
1472 			   */
1473 			bcopy(&field->buffers[0].string[pos + 1],
1474 			      &field->buffers[0].string[pos],
1475 			      field->buffers[0].length - pos);
1476 			field->buffers[0].length--;
1477 			bump_lines(field, (int) pos, -1, TRUE);
1478 			if (pos > 0)
1479 				pos--;
1480 		} else if (field->overlay == 1) {
1481 			  /* back out character overlay */
1482 			field->buffers[0].string[pos] = old_c;
1483 		}
1484 
1485 		new_size = find_cur_line(field, pos);
1486 		_formi_calculate_tabs(field, new_size);
1487 
1488 		_formi_wrap_field(field, pos);
1489 		  /*
1490 		   * If we are here then either the status is bad or we
1491 		   * simply ran out of room.  If the status is E_OK then
1492 		   * we ran out of room, let the form driver know this.
1493 		   */
1494 		if (status == E_OK)
1495 			status = E_REQUEST_DENIED;
1496 
1497 	} else {
1498 		field->buf0_status = TRUE;
1499 		if ((field->rows + field->nrows) == 1) {
1500 			field->row_xpos++;
1501 			status = _formi_set_cursor_xpos(field, FALSE);
1502 		} else {
1503 			if (new_size >= field->rows) {
1504 				field->cursor_ypos = field->rows - 1;
1505 				field->start_line = field->row_count
1506 					- field->cursor_ypos - 1;
1507 			} else
1508 				field->cursor_ypos = new_size;
1509 
1510 			if ((field->lines[new_size].start) <= (pos + 1)) {
1511 				field->row_xpos = pos
1512 					- field->lines[new_size].start + 1;
1513 				field->cursor_xpos =
1514 					_formi_tab_expanded_length(
1515 						&field->buffers[0].string[
1516 						    field->lines[new_size].start], 0,
1517 						field->row_xpos - 1);
1518 			} else {
1519 				field->row_xpos = 0;
1520 				field->cursor_xpos = 0;
1521 			}
1522 
1523 			  /*
1524 			   * Annoying corner case - if we are right in
1525 			   * the bottom right corner of the field we
1526 			   * need to scroll the field one line so the
1527 			   * cursor is positioned correctly in the
1528 			   * field.
1529 			   */
1530 			if ((field->cursor_xpos >= field->cols) &&
1531 			    (field->cursor_ypos == (field->rows - 1))) {
1532 				field->cursor_ypos--;
1533 				field->start_line++;
1534 			}
1535 		}
1536 	}
1537 
1538 #ifdef DEBUG
1539 	assert((field->cursor_xpos <= field->cols)
1540 	       && (field->cursor_ypos < 400000)
1541 	       && (field->start_line < 400000));
1542 
1543 	fprintf(dbg, "add_char exit: xpos=%d, row_pos=%d, start=%d\n",
1544 		field->cursor_xpos, field->row_xpos, field->start_char);
1545 	fprintf(dbg, "add_char_exit: length=%d(%d), allocated=%d\n",
1546 		field->buffers[0].length, strlen(field->buffers[0].string),
1547 		field->buffers[0].allocated);
1548 	fprintf(dbg, "add_char exit: ypos=%d, start_line=%d\n",
1549 		field->cursor_ypos, field->start_line);
1550 	fprintf(dbg,"add_char exit: %s\n", field->buffers[0].string);
1551 	fprintf(dbg, "add_char exit: buf0_status=%d\n", field->buf0_status);
1552 	fprintf(dbg, "add_char exit: status = %s\n",
1553 		(status == E_OK)? "OK" : "FAILED");
1554 #endif
1555 	return status;
1556 }
1557 
1558 /*
1559  * Set the position of the cursor on the screen in the row depending on
1560  * where the current position in the string is and the justification
1561  * that is to be applied to the field.  Justification is only applied
1562  * to single row, static fields.
1563  */
1564 static int
1565 _formi_set_cursor_xpos(FIELD *field, int noscroll)
1566 {
1567 	int just, pos;
1568 
1569 	just = field->justification;
1570 	pos = field->start_char + field->row_xpos
1571 	   + field->lines[field->start_line + field->cursor_ypos].start;
1572 
1573 #ifdef DEBUG
1574 	fprintf(dbg,
1575 	  "cursor_xpos enter: pos %d, start_char %d, row_xpos %d, xpos %d\n",
1576 		pos, field->start_char, field->row_xpos, field->cursor_xpos);
1577 #endif
1578 
1579 	  /*
1580 	   * make sure we apply the correct justification to non-static
1581 	   * fields.
1582 	   */
1583 	if (((field->rows + field->nrows) != 1) ||
1584 	    ((field->opts & O_STATIC) != O_STATIC))
1585 		just = JUSTIFY_LEFT;
1586 
1587 	switch (just) {
1588 	case JUSTIFY_RIGHT:
1589 		field->cursor_xpos = field->cols - 1
1590 			- _formi_tab_expanded_length(
1591 				field->buffers[0].string, 0,
1592 				field->buffers[0].length - 1)
1593 			+ _formi_tab_expanded_length(
1594 				field->buffers[0].string, 0,
1595 				field->row_xpos);
1596 		break;
1597 
1598 	case JUSTIFY_CENTER:
1599 		field->cursor_xpos = ((field->cols - 1)
1600 			- _formi_tab_expanded_length(
1601 				field->buffers[0].string, 0,
1602 				field->buffers[0].length - 1) + 1) / 2
1603 			+ _formi_tab_expanded_length(field->buffers[0].string,
1604 						     0, field->row_xpos);
1605 
1606 		if (field->cursor_xpos > (field->cols - 1))
1607 			field->cursor_xpos = (field->cols - 1);
1608 		break;
1609 
1610 	default:
1611 		field->cursor_xpos = _formi_tab_expanded_length(
1612 			field->buffers[0].string,
1613 			field->start_char,
1614 			field->row_xpos	+ field->start_char);
1615 		if ((field->cursor_xpos <= (field->cols - 1)) &&
1616 		    ((field->start_char + field->row_xpos)
1617 		     < field->buffers[0].length))
1618 			field->cursor_xpos--;
1619 
1620 		if (field->cursor_xpos > (field->cols - 1)) {
1621 			if ((field->opts & O_STATIC) == O_STATIC) {
1622 				field->start_char = 0;
1623 
1624 				if (field->row_xpos
1625 				    == (field->buffers[0].length - 1)) {
1626 					field->cursor_xpos = field->cols - 1;
1627 				} else {
1628 					field->cursor_xpos =
1629 						_formi_tab_expanded_length(
1630 						  field->buffers[0].string,
1631 						  field->start_char,
1632 						  field->row_xpos
1633 						    + field->start_char
1634 						  - 1) - 1;
1635 				}
1636 			} else {
1637 				if (noscroll == FALSE) {
1638 					field->start_char =
1639 						tab_fit_window(
1640 							field,
1641 							field->start_char
1642 							+ field->row_xpos,
1643 							field->cols);
1644 					field->row_xpos = pos
1645 						- field->start_char;
1646 					field->cursor_xpos =
1647 						_formi_tab_expanded_length(
1648 						   field->buffers[0].string,
1649 						   field->start_char,
1650 						   field->row_xpos
1651 						      + field->start_char - 1);
1652 				} else {
1653 					field->cursor_xpos = (field->cols - 1);
1654 				}
1655 			}
1656 
1657 		}
1658 		break;
1659 	}
1660 
1661 #ifdef DEBUG
1662 	fprintf(dbg,
1663 	  "cursor_xpos exit: pos %d, start_char %d, row_xpos %d, xpos %d\n",
1664 		pos, field->start_char, field->row_xpos, field->cursor_xpos);
1665 #endif
1666 	return E_OK;
1667 }
1668 
1669 /*
1670  * Manipulate the text in a field, this takes the given form and performs
1671  * the passed driver command on the current text field.  Returns 1 if the
1672  * text field was modified.
1673  */
1674 int
1675 _formi_manipulate_field(FORM *form, int c)
1676 {
1677 	FIELD *cur;
1678 	char *str, saved;
1679 	unsigned int start, end, pos, row, status, old_count, size;
1680 	unsigned int old_xpos, old_row_pos;
1681 	int len;
1682 
1683 	cur = form->fields[form->cur_field];
1684 	if ((cur->buffers[0].string == NULL) || (cur->buffers[0].length == 0))
1685 		return E_REQUEST_DENIED;
1686 
1687 #ifdef DEBUG
1688 	fprintf(dbg, "entry: request is REQ_%s\n", reqs[c - REQ_MIN_REQUEST]);
1689 	fprintf(dbg,
1690 	"entry: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
1691 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
1692 		cur->buffers[0].length,	cur->buffers[0].allocated);
1693 	fprintf(dbg, "entry: start_line=%d, ypos=%d\n", cur->start_line,
1694 		cur->cursor_ypos);
1695 	fprintf(dbg, "entry: string=");
1696 	if (cur->buffers[0].string == NULL)
1697 		fprintf(dbg, "(null)\n");
1698 	else
1699 		fprintf(dbg, "\"%s\"\n", cur->buffers[0].string);
1700 #endif
1701 
1702 	  /* Cannot manipulate a null string! */
1703 	if (cur->buffers[0].string == NULL)
1704 		return E_REQUEST_DENIED;
1705 
1706 	row = cur->start_line + cur->cursor_ypos;
1707 	saved = cur->buffers[0].string[cur->start_char + cur->row_xpos
1708 				      + cur->lines[row].start];
1709 
1710 	switch (c) {
1711 	case REQ_RIGHT_CHAR:
1712 		  /*
1713 		   * The right_char request performs the same function
1714 		   * as the next_char request except that the cursor is
1715 		   * not wrapped if it is at the end of the line, so
1716 		   * check if the cursor is at the end of the line and
1717 		   * deny the request otherwise just fall through to
1718 		   * the next_char request handler.
1719 		   */
1720 		if (cur->cursor_xpos >= cur->cols - 1)
1721 			return E_REQUEST_DENIED;
1722 
1723 		  /* FALLTHRU */
1724 
1725 	case REQ_NEXT_CHAR:
1726 		  /* for a dynamic field allow an offset of one more
1727 		   * char so we can insert chars after end of string.
1728 		   * Static fields cannot do this so deny request if
1729 		   * cursor is at the end of the field.
1730 		   */
1731 		if (((cur->opts & O_STATIC) == O_STATIC) &&
1732 		    (cur->row_xpos == cur->cols - 1) &&
1733 		    ((cur->rows + cur->nrows) == 1))
1734 			return E_REQUEST_DENIED;
1735 
1736 		if ((cur->row_xpos + cur->start_char + 1)
1737 		    > cur->buffers[0].length)
1738 			return E_REQUEST_DENIED;
1739 
1740 		if ((cur->rows + cur->nrows) == 1) {
1741 			cur->row_xpos++;
1742 			_formi_set_cursor_xpos(cur, (c == REQ_RIGHT_CHAR));
1743 		} else {
1744 			if (cur->cursor_xpos >= (cur->lines[row].length - 1)) {
1745 				if (((row + 1) >= cur->row_count) ||
1746 				    (c == REQ_RIGHT_CHAR))
1747 					return E_REQUEST_DENIED;
1748 
1749 				cur->cursor_xpos = 0;
1750 				cur->row_xpos = 0;
1751 				if (cur->cursor_ypos == (cur->rows - 1))
1752 					cur->start_line++;
1753 				else
1754 					cur->cursor_ypos++;
1755 			} else {
1756 				old_xpos = cur->cursor_xpos;
1757 				old_row_pos = cur->row_xpos;
1758 				if (saved == '\t')
1759 					cur->cursor_xpos += tab_size(cur,
1760 							cur->lines[row].start,
1761 							cur->row_xpos);
1762 				else
1763 					cur->cursor_xpos++;
1764 				cur->row_xpos++;
1765 				if (cur->cursor_xpos
1766 				    >= cur->lines[row].length) {
1767 					if (((row + 1) >= cur->row_count) ||
1768 					    (c == REQ_RIGHT_CHAR)) {
1769 						cur->cursor_xpos = old_xpos;
1770 						cur->row_xpos = old_row_pos;
1771 						return E_REQUEST_DENIED;
1772 					}
1773 
1774 					cur->cursor_xpos = 0;
1775 					cur->row_xpos = 0;
1776 					if (cur->cursor_ypos
1777 					    == (cur->rows - 1))
1778 						cur->start_line++;
1779 					else
1780 						cur->cursor_ypos++;
1781 				}
1782 			}
1783 		}
1784 
1785 		break;
1786 
1787 	case REQ_LEFT_CHAR:
1788 		  /*
1789 		   * The behaviour of left_char is the same as prev_char
1790 		   * except that the cursor will not wrap if it has
1791 		   * reached the LHS of the field, so just check this
1792 		   * and fall through if we are not at the LHS.
1793 		   */
1794 		if (cur->cursor_xpos == 0)
1795 			return E_REQUEST_DENIED;
1796 
1797 		  /* FALLTHRU */
1798 	case REQ_PREV_CHAR:
1799 		if ((cur->rows + cur->nrows) == 1) {
1800 			if (cur->row_xpos == 0) {
1801 				if (cur->start_char > 0)
1802 					cur->start_char--;
1803 				else
1804 					return E_REQUEST_DENIED;
1805 			} else {
1806 				cur->row_xpos--;
1807 				_formi_set_cursor_xpos(cur, FALSE);
1808 			}
1809 		} else {
1810 			if ((cur->cursor_xpos == 0) &&
1811 			    (cur->cursor_ypos == 0) &&
1812 			    (cur->start_line == 0))
1813 				return E_REQUEST_DENIED;
1814 
1815 			row = cur->start_line + cur->cursor_ypos;
1816 			pos = cur->lines[row].start + cur->row_xpos;
1817 			if ((pos >= cur->buffers[0].length) && (pos > 0))
1818 				pos--;
1819 
1820 			if (cur->cursor_xpos > 0) {
1821 				if (cur->buffers[0].string[pos] == '\t') {
1822 					size = tab_size(cur,
1823 							cur->lines[row].start,
1824 							pos
1825 							- cur->lines[row].start);
1826 					if (size > cur->cursor_xpos) {
1827 						cur->cursor_xpos = 0;
1828 						cur->row_xpos = 0;
1829 					} else {
1830 						cur->row_xpos--;
1831 						cur->cursor_xpos -= size;
1832 					}
1833 				} else {
1834 					cur->cursor_xpos--;
1835 					cur->row_xpos--;
1836 				}
1837 			} else {
1838 				if (cur->cursor_ypos > 0)
1839 					cur->cursor_ypos--;
1840 				else
1841 					cur->start_line--;
1842 				row = cur->start_line + cur->cursor_ypos;
1843 				cur->cursor_xpos = cur->lines[row].length - 1;
1844 				cur->row_xpos = cur->lines[row].end -
1845 					cur->lines[row].start;
1846 			}
1847 		}
1848 
1849 		break;
1850 
1851 	case REQ_DOWN_CHAR:
1852 		  /*
1853 		   * The down_char request has the same functionality as
1854 		   * the next_line request excepting that the field is not
1855 		   * scrolled if the cursor is at the bottom of the field.
1856 		   * Check to see if the cursor is at the bottom of the field
1857 		   * and if it is then deny the request otherwise fall
1858 		   * through to the next_line handler.
1859 		   */
1860 		if (cur->cursor_ypos >= cur->rows - 1)
1861 			return E_REQUEST_DENIED;
1862 
1863 		  /* FALLTHRU */
1864 
1865 	case REQ_NEXT_LINE:
1866 		if ((cur->start_line + cur->cursor_ypos + 1) >= cur->row_count)
1867 			return E_REQUEST_DENIED;
1868 
1869 		if ((cur->cursor_ypos + 1) >= cur->rows) {
1870 			cur->start_line++;
1871 		} else
1872 			cur->cursor_ypos++;
1873 		row = cur->cursor_ypos + cur->start_line;
1874 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos)
1875 			- cur->lines[row].start;
1876 		cur->cursor_xpos =
1877 			_formi_tab_expanded_length(
1878 				&cur->buffers[0].string[cur->lines[row].start],
1879 				0, cur->row_xpos);
1880 		break;
1881 
1882 	case REQ_UP_CHAR:
1883 		  /*
1884 		   * The up_char request has the same functionality as
1885 		   * the prev_line request excepting the field is not
1886 		   * scrolled, check if the cursor is at the top of the
1887 		   * field, if it is deny the request otherwise fall
1888 		   * through to the prev_line handler.
1889 		   */
1890 		if (cur->cursor_ypos == 0)
1891 			return E_REQUEST_DENIED;
1892 
1893 		  /* FALLTHRU */
1894 
1895 	case REQ_PREV_LINE:
1896 		if (cur->cursor_ypos == 0) {
1897 			if (cur->start_line == 0)
1898 				return E_REQUEST_DENIED;
1899 			cur->start_line--;
1900 		} else
1901 			cur->cursor_ypos--;
1902 		row = cur->cursor_ypos + cur->start_line;
1903 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos + 1)
1904 			- cur->lines[row].start;
1905 		cur->cursor_xpos =
1906 			_formi_tab_expanded_length(
1907 				&cur->buffers[0].string[cur->lines[row].start],
1908 				0, cur->row_xpos) - 1;
1909 		break;
1910 
1911 	case REQ_NEXT_WORD:
1912 		start = cur->lines[cur->start_line + cur->cursor_ypos].start
1913 			+ cur->row_xpos + cur->start_char;
1914 		str = cur->buffers[0].string;
1915 
1916 		start = find_eow(str, start);
1917 
1918 		  /* check if we hit the end */
1919 		if (str[start] == '\0')
1920 			return E_REQUEST_DENIED;
1921 
1922 		  /* otherwise we must have found the start of a word...*/
1923 		if ((cur->rows + cur->nrows) == 1) {
1924 			  /* single line field */
1925 			size = _formi_tab_expanded_length(str,
1926 				cur->start_char, start);
1927 			if (size < cur->cols) {
1928 				cur->row_xpos = start - cur->start_char;
1929 			} else {
1930 				cur->start_char = start;
1931 				cur->row_xpos = 0;
1932 			}
1933 			_formi_set_cursor_xpos(cur, FALSE);
1934 	} else {
1935 			  /* multiline field */
1936 			row = find_cur_line(cur, start);
1937 			cur->row_xpos = start - cur->lines[row].start;
1938 			cur->cursor_xpos = _formi_tab_expanded_length(
1939 				&str[cur->lines[row].start],
1940 				0, cur->row_xpos) - 1;
1941 			if (row != (cur->start_line + cur->cursor_ypos)) {
1942 				if (cur->cursor_ypos == (cur->rows - 1)) {
1943 					cur->start_line = row - cur->rows + 1;
1944 				} else {
1945 					cur->cursor_ypos = row
1946 						- cur->start_line;
1947 				}
1948 			}
1949 		}
1950 		break;
1951 
1952 	case REQ_PREV_WORD:
1953 		start = cur->start_char + cur->row_xpos
1954 			+ cur->lines[cur->start_line + cur->cursor_ypos].start;
1955 		if (cur->start_char > 0)
1956 			start--;
1957 
1958 		if (start == 0)
1959 			return E_REQUEST_DENIED;
1960 
1961 		str = cur->buffers[0].string;
1962 
1963 		start = find_sow(str, start);
1964 
1965 		if ((cur->rows + cur->nrows) == 1) {
1966 			  /* single line field */
1967 			size = _formi_tab_expanded_length(str,
1968 				cur->start_char, start);
1969 
1970 			if (start > cur->start_char) {
1971 				cur->row_xpos = start - cur->start_char;
1972 			} else {
1973 				cur->start_char = start;
1974 				cur->row_xpos = 0;
1975 			}
1976 			_formi_set_cursor_xpos(cur, FALSE);
1977 		} else {
1978 			  /* multiline field */
1979 			row = find_cur_line(cur, start);
1980 			cur->row_xpos = start - cur->lines[row].start;
1981 			cur->cursor_xpos = _formi_tab_expanded_length(
1982 				&str[cur->lines[row].start], 0,
1983 				cur->row_xpos) - 1;
1984 			if (row != (cur->start_line + cur->cursor_ypos)) {
1985 				if (cur->cursor_ypos == 0) {
1986 					cur->start_line = row;
1987 				} else {
1988 					if (cur->start_line > row) {
1989 						cur->start_line = row;
1990 						cur->cursor_ypos = 0;
1991 					} else {
1992 						cur->cursor_ypos = row -
1993 							cur->start_line;
1994 					}
1995 				}
1996 			}
1997 		}
1998 
1999 		break;
2000 
2001 	case REQ_BEG_FIELD:
2002 		cur->start_char = 0;
2003 		cur->start_line = 0;
2004 		cur->row_xpos = 0;
2005 		_formi_init_field_xpos(cur);
2006 		cur->cursor_ypos = 0;
2007 		break;
2008 
2009 	case REQ_BEG_LINE:
2010 		cur->row_xpos = 0;
2011 		_formi_init_field_xpos(cur);
2012 		cur->start_char = 0;
2013 		break;
2014 
2015 	case REQ_END_FIELD:
2016 		if (cur->row_count > cur->rows) {
2017 			cur->start_line = cur->row_count - cur->rows;
2018 			cur->cursor_ypos = cur->rows - 1;
2019 		} else {
2020 			cur->start_line = 0;
2021 			cur->cursor_ypos = cur->row_count - 1;
2022 		}
2023 
2024 		  /* we fall through here deliberately, we are on the
2025 		   * correct row, now we need to get to the end of the
2026 		   * line.
2027 		   */
2028 		  /* FALLTHRU */
2029 
2030 	case REQ_END_LINE:
2031 		row = cur->start_line + cur->cursor_ypos;
2032 		start = cur->lines[row].start;
2033 		end = cur->lines[row].end;
2034 
2035 		if ((cur->rows + cur->nrows) == 1) {
2036 			if (cur->lines[row].length > cur->cols - 1) {
2037 				if ((cur->opts & O_STATIC) != O_STATIC) {
2038 					cur->start_char = tab_fit_window(
2039 						cur, end, cur->cols) + 1;
2040 					cur->row_xpos = cur->buffers[0].length
2041 						- cur->start_char;
2042 				} else {
2043 					cur->start_char = 0;
2044 					cur->row_xpos = cur->cols - 1;
2045 				}
2046 			} else {
2047 				cur->row_xpos = end + 1;
2048 				cur->start_char = 0;
2049 			}
2050 			_formi_set_cursor_xpos(cur, FALSE);
2051 		} else {
2052 			cur->row_xpos = end - start;
2053 			cur->cursor_xpos = cur->lines[row].length - 1;
2054 			if (row == (cur->row_count - 1)) {
2055 				cur->row_xpos++;
2056 				cur->cursor_xpos++;
2057 			}
2058 		}
2059 		break;
2060 
2061 	case REQ_NEW_LINE:
2062 		if ((status = split_line(cur,
2063 				cur->start_char + cur->row_xpos)) != E_OK)
2064 			return status;
2065 		break;
2066 
2067 	case REQ_INS_CHAR:
2068 		if ((status = _formi_add_char(cur, cur->start_char
2069 					      + cur->row_xpos,
2070 					      cur->pad)) != E_OK)
2071 			return status;
2072 		break;
2073 
2074 	case REQ_INS_LINE:
2075 		start = cur->lines[cur->start_line + cur->cursor_ypos].start;
2076 		if ((status = split_line(cur, start)) != E_OK)
2077 			return status;
2078 		break;
2079 
2080 	case REQ_DEL_CHAR:
2081 		if (cur->buffers[0].length == 0)
2082 			return E_REQUEST_DENIED;
2083 
2084 		row = cur->start_line + cur->cursor_ypos;
2085 		start = cur->start_char + cur->row_xpos
2086 			+ cur->lines[row].start;
2087 		end = cur->buffers[0].length;
2088 		if (start >= cur->buffers[0].length)
2089 			return E_REQUEST_DENIED;
2090 
2091 		if (start == cur->lines[row].end) {
2092 			if ((cur->rows + cur->nrows) > 1) {
2093 				/*
2094 				 * If we have more than one row, join the
2095 				 * next row to make things easier unless
2096 				 * we are at the end of the string, in
2097 				 * that case the join would fail but we
2098 				 * really want to delete the last char
2099 				 * in the field.
2100 				 */
2101 				if ((cur->row_count > 1)
2102 				    && (start != (end - 1))) {
2103 					if (_formi_join_line(cur,
2104 							     start,
2105 							     JOIN_NEXT_NW)
2106 					    != E_OK) {
2107 						return E_REQUEST_DENIED;
2108 					}
2109 				}
2110 			}
2111 		}
2112 
2113 		saved = cur->buffers[0].string[start];
2114 		bcopy(&cur->buffers[0].string[start + 1],
2115 		      &cur->buffers[0].string[start],
2116 		      (unsigned) end - start + 1);
2117 		bump_lines(cur, _FORMI_USE_CURRENT, -1, TRUE);
2118 		cur->buffers[0].length--;
2119 
2120 		  /*
2121 		   * recalculate tabs for a single line field, multiline
2122 		   * fields will do this when the field is wrapped.
2123 		   */
2124 		if ((cur->rows + cur->nrows) == 1)
2125 			_formi_calculate_tabs(cur, 0);
2126 		  /*
2127 		   * if we are at the end of the string then back the
2128 		   * cursor pos up one to stick on the end of the line
2129 		   */
2130 		if (start == cur->buffers[0].length) {
2131 			if (cur->buffers[0].length > 1) {
2132 				if ((cur->rows + cur->nrows) == 1) {
2133 					pos = cur->row_xpos + cur->start_char;
2134 					cur->start_char =
2135 						tab_fit_window(
2136 							cur,
2137 							cur->start_char + cur->row_xpos,
2138 							cur->cols);
2139 					cur->row_xpos = pos - cur->start_char
2140 						- 1;
2141 					_formi_set_cursor_xpos(cur, FALSE);
2142 				} else {
2143 					if (cur->row_xpos == 0) {
2144 						if (cur->lines[row].start !=
2145 						    cur->buffers[0].length) {
2146 							if (_formi_join_line(
2147 								cur,
2148 								cur->lines[row].start,
2149 								JOIN_PREV_NW)
2150 							    != E_OK) {
2151 								return E_REQUEST_DENIED;
2152 							}
2153 						} else {
2154 							if (cur->row_count > 1)
2155 								cur->row_count--;
2156 						}
2157 
2158 						row = cur->start_line
2159 							+ cur->cursor_ypos;
2160 						if (row > 0)
2161 							row--;
2162 					}
2163 
2164 					cur->row_xpos = start
2165 						- cur->lines[row].start - 1;
2166 					cur->cursor_xpos =
2167 						_formi_tab_expanded_length(
2168 							&cur->buffers[0].string[cur->lines[row].start],
2169 							0, cur->row_xpos);
2170 					if ((cur->cursor_xpos > 0)
2171 					    && (start != (cur->buffers[0].length - 1)))
2172 						cur->cursor_xpos--;
2173 					if (row >= cur->rows)
2174 						cur->start_line = row
2175 							- cur->cursor_ypos;
2176 					else {
2177 						cur->start_line = 0;
2178 						cur->cursor_ypos = row;
2179 					}
2180 				}
2181 
2182 				start--;
2183 			} else {
2184 				start = 0;
2185 				cur->row_xpos = 0;
2186 				_formi_init_field_xpos(cur);
2187 			}
2188 		}
2189 
2190 		if ((cur->rows + cur->nrows) > 1) {
2191 			if (_formi_wrap_field(cur, start) != E_OK) {
2192 				bcopy(&cur->buffers[0].string[start],
2193 				      &cur->buffers[0].string[start + 1],
2194 				      (unsigned) end - start);
2195 				cur->buffers[0].length++;
2196 				cur->buffers[0].string[start] = saved;
2197 				bump_lines(cur, _FORMI_USE_CURRENT, 1, TRUE);
2198 				_formi_wrap_field(cur, start);
2199 				return E_REQUEST_DENIED;
2200 			}
2201 		}
2202 		break;
2203 
2204 	case REQ_DEL_PREV:
2205 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0)
2206 		    && (cur->start_line == 0) && (cur->cursor_ypos == 0))
2207 			   return E_REQUEST_DENIED;
2208 
2209 		row = cur->start_line + cur->cursor_ypos;
2210 		start = cur->row_xpos + cur->start_char
2211 			+ cur->lines[row].start;
2212 		end = cur->buffers[0].length;
2213 
2214 		if ((cur->start_char + cur->row_xpos) == 0) {
2215 			  /*
2216 			   * Join this line to the next one, but only if
2217 			   * we are not at the end of the string because
2218 			   * in that case there are no characters to join.
2219 			   */
2220 			if (cur->lines[row].start != end) {
2221 				if (_formi_join_line(cur,
2222 						     cur->lines[row].start,
2223 						     JOIN_PREV_NW) != E_OK) {
2224 					return E_REQUEST_DENIED;
2225 				}
2226 			} else {
2227 				/* but we do want the row count decremented */
2228 				if (cur->row_count > 1)
2229 					cur->row_count--;
2230 			}
2231 		}
2232 
2233 		saved = cur->buffers[0].string[start - 1];
2234 		bcopy(&cur->buffers[0].string[start],
2235 		      &cur->buffers[0].string[start - 1],
2236 		      (unsigned) end - start + 1);
2237 		bump_lines(cur, (int) start - 1, -1, TRUE);
2238 		cur->buffers[0].length--;
2239 
2240 		if ((cur->rows + cur->nrows) == 1) {
2241 			_formi_calculate_tabs(cur, 0);
2242 			pos = cur->row_xpos + cur->start_char;
2243 			if (pos > 0)
2244 				pos--;
2245 			cur->start_char =
2246 				tab_fit_window(cur,
2247 					       cur->start_char + cur->row_xpos,
2248 					       cur->cols);
2249 			cur->row_xpos = pos - cur->start_char;
2250 			_formi_set_cursor_xpos(cur, FALSE);
2251 		} else {
2252 			pos = start - 1;
2253 			if (pos >= cur->buffers[0].length)
2254 				pos = cur->buffers[0].length - 1;
2255 
2256 			if ((_formi_wrap_field(cur, pos) != E_OK)) {
2257 				bcopy(&cur->buffers[0].string[start - 1],
2258 				      &cur->buffers[0].string[start],
2259 				      (unsigned) end - start);
2260 				cur->buffers[0].length++;
2261 				cur->buffers[0].string[start - 1] = saved;
2262 				bump_lines(cur, (int) start - 1, 1, TRUE);
2263 				_formi_wrap_field(cur, pos);
2264 				return E_REQUEST_DENIED;
2265 			}
2266 
2267 			row = find_cur_line(cur, pos);
2268 			cur->row_xpos = start - cur->lines[row].start - 1;
2269 			cur->cursor_xpos = _formi_tab_expanded_length(
2270 				&cur->buffers[0].string[cur->lines[row].start],
2271 				0, cur->row_xpos);
2272 			if ((cur->cursor_xpos > 0)
2273 			    && (pos != (cur->buffers[0].length - 1)))
2274 				cur->cursor_xpos--;
2275 
2276 			if (row >= cur->rows)
2277 				cur->start_line = row - cur->cursor_ypos;
2278 			else {
2279 				cur->start_line = 0;
2280 				cur->cursor_ypos = row;
2281 			}
2282 		}
2283 		break;
2284 
2285 	case REQ_DEL_LINE:
2286 		row = cur->start_line + cur->cursor_ypos;
2287 		start = cur->lines[row].start;
2288 		end = cur->lines[row].end;
2289 		bcopy(&cur->buffers[0].string[end + 1],
2290 		      &cur->buffers[0].string[start],
2291 		      (unsigned) cur->buffers[0].length - end + 1);
2292 
2293 		if (((cur->rows + cur->nrows) == 1) ||
2294 		    (cur->row_count == 1)) {
2295 			  /* single line case */
2296 			cur->buffers[0].length = 0;
2297 			cur->lines[0].end = cur->lines[0].length = 0;
2298 			cur->row_xpos = 0;
2299 			_formi_init_field_xpos(cur);
2300 			cur->cursor_ypos = 0;
2301 		} else {
2302 			  /* multiline field */
2303 			old_count = cur->row_count;
2304 			cur->row_count--;
2305 			if (cur->row_count == 0)
2306 				cur->row_count = 1;
2307 
2308 			if (cur->row_count > 1)
2309 				bcopy(&cur->lines[row + 1],
2310 				      &cur->lines[row],
2311 				      (unsigned) (cur->row_count - row)
2312 				      * sizeof(struct _formi_field_lines));
2313 
2314 			cur->lines[row].start = start;
2315 			len = start - end - 1; /* yes, this is negative */
2316 
2317 			if (row < (cur->row_count - 1))
2318 				bump_lines(cur, (int) start, len, FALSE);
2319 			else if (old_count == 1) {
2320 				cur->lines[0].end = cur->lines[0].length = 0;
2321 				cur->cursor_xpos = 0;
2322 				cur->row_xpos = 0;
2323 				cur->cursor_ypos = 0;
2324 			} else if (cur->row_count == 1) {
2325 				cur->lines[0].length = cur->buffers[0].length
2326 					+ len;
2327 				cur->lines[0].end = cur->lines[0].length - 1;
2328 			}
2329 
2330 			cur->buffers[0].length += len;
2331 
2332 			if (row > (cur->row_count - 1)) {
2333 				row--;
2334 				if (cur->cursor_ypos == 0) {
2335 					if (cur->start_line > 0) {
2336 						cur->start_line--;
2337 					}
2338 				} else {
2339 					cur->cursor_ypos--;
2340 				}
2341 			}
2342 
2343 			if (old_count > 1) {
2344 				if (cur->cursor_xpos > cur->lines[row].length) {
2345 					cur->cursor_xpos =
2346 						cur->lines[row].length - 1;
2347 					cur->row_xpos = cur->lines[row].end;
2348 				}
2349 
2350 				if (row >= cur->rows)
2351 					cur->start_line = row
2352 						- cur->cursor_ypos;
2353 				else {
2354 					cur->start_line = 0;
2355 					cur->cursor_ypos = row;
2356 				}
2357 			}
2358 		}
2359 		break;
2360 
2361 	case REQ_DEL_WORD:
2362 		start = cur->start_char + cur->row_xpos
2363 			+ cur->lines[row].start;
2364 		str = cur->buffers[0].string;
2365 
2366 		end = find_eow(str, start);
2367 
2368 		  /*
2369 		   * If not at the start of a word then find the start,
2370 		   * we cannot blindly call find_sow because this will
2371 		   * skip back a word if we are already at the start of
2372 		   * a word.
2373 		   */
2374 		if ((start > 0)
2375 		    && !(isblank(str[start - 1]) && !isblank(str[start])))
2376 			start = find_sow(cur->buffers[0].string, start);
2377 		bcopy(&cur->buffers[0].string[end],
2378 		      &cur->buffers[0].string[start],
2379 		      (unsigned) cur->buffers[0].length - end + 1);
2380 		len = end - start;
2381 		cur->buffers[0].length -= len;
2382 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2383 
2384 		if ((cur->rows + cur->nrows) > 1) {
2385 			row = cur->start_line + cur->cursor_ypos;
2386 			if ((row + 1) < cur->row_count) {
2387 				/*
2388 				 * if not on the last row we need to
2389 				 * join on the next row so the line
2390 				 * will be re-wrapped.
2391 				 */
2392 				_formi_join_line(cur, cur->lines[row].end,
2393 						 JOIN_NEXT_NW);
2394 			}
2395 			_formi_wrap_field(cur, start);
2396 			row = find_cur_line(cur, start);
2397 			cur->row_xpos = start - cur->lines[row].start;
2398 			cur->cursor_xpos = _formi_tab_expanded_length(
2399 				&cur->buffers[0].string[cur->lines[row].start],
2400 				0, cur->row_xpos);
2401 			if ((cur->cursor_xpos > 0)
2402 			    && (start != (cur->buffers[0].length - 1)))
2403 				cur->cursor_xpos--;
2404 		} else {
2405 			_formi_calculate_tabs(cur, 0);
2406 			cur->row_xpos = start - cur->start_char;
2407 			if (cur->row_xpos > 0)
2408 				cur->row_xpos--;
2409 			_formi_set_cursor_xpos(cur, FALSE);
2410 		}
2411 		break;
2412 
2413 	case REQ_CLR_EOL:
2414 		row = cur->start_line + cur->cursor_ypos;
2415 		start = cur->start_char + cur->cursor_xpos;
2416 		end = cur->lines[row].end;
2417 		len = end - start;
2418 		bcopy(&cur->buffers[0].string[end + 1],
2419 		      &cur->buffers[0].string[start],
2420 		      cur->buffers[0].length - end + 1);
2421 		cur->buffers[0].length -= len;
2422 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2423 
2424 		if (cur->row_xpos > cur->lines[row].length) {
2425 			cur->row_xpos = cur->lines[row].end;
2426 			if (cur->rows + cur->nrows == 1)
2427 				_formi_set_cursor_xpos(cur, FALSE);
2428 			else
2429 				cur->cursor_xpos = cur->lines[row].length;
2430 		}
2431 		break;
2432 
2433 	case REQ_CLR_EOF:
2434 		row = cur->start_line + cur->cursor_ypos;
2435 		cur->buffers[0].string[cur->start_char
2436 				      + cur->cursor_xpos] = '\0';
2437 		cur->buffers[0].length = strlen(cur->buffers[0].string);
2438 		cur->lines[row].end = cur->buffers[0].length;
2439 		cur->lines[row].length = cur->lines[row].end
2440 			- cur->lines[row].start;
2441 		break;
2442 
2443 	case REQ_CLR_FIELD:
2444 		cur->buffers[0].string[0] = '\0';
2445 		cur->buffers[0].length = 0;
2446 		cur->row_count = 1;
2447 		cur->start_line = 0;
2448 		cur->cursor_ypos = 0;
2449 		cur->row_xpos = 0;
2450 		_formi_init_field_xpos(cur);
2451 		cur->start_char = 0;
2452 		cur->lines[0].start = 0;
2453 		cur->lines[0].end = 0;
2454 		cur->lines[0].length = 0;
2455 		break;
2456 
2457 	case REQ_OVL_MODE:
2458 		cur->overlay = 1;
2459 		break;
2460 
2461 	case REQ_INS_MODE:
2462 		cur->overlay = 0;
2463 		break;
2464 
2465 	case REQ_SCR_FLINE:
2466 		_formi_scroll_fwd(cur, 1);
2467 		break;
2468 
2469 	case REQ_SCR_BLINE:
2470 		_formi_scroll_back(cur, 1);
2471 		break;
2472 
2473 	case REQ_SCR_FPAGE:
2474 		_formi_scroll_fwd(cur, cur->rows);
2475 		break;
2476 
2477 	case REQ_SCR_BPAGE:
2478 		_formi_scroll_back(cur, cur->rows);
2479 		break;
2480 
2481 	case REQ_SCR_FHPAGE:
2482 		_formi_scroll_fwd(cur, cur->rows / 2);
2483 		break;
2484 
2485 	case REQ_SCR_BHPAGE:
2486 		_formi_scroll_back(cur, cur->rows / 2);
2487 		break;
2488 
2489 	case REQ_SCR_FCHAR:
2490 		_formi_hscroll_fwd(cur, 1);
2491 		break;
2492 
2493 	case REQ_SCR_BCHAR:
2494 		_formi_hscroll_back(cur, 1);
2495 		break;
2496 
2497 	case REQ_SCR_HFLINE:
2498 		_formi_hscroll_fwd(cur, cur->cols);
2499 		break;
2500 
2501 	case REQ_SCR_HBLINE:
2502 		_formi_hscroll_back(cur, cur->cols);
2503 		break;
2504 
2505 	case REQ_SCR_HFHALF:
2506 		_formi_hscroll_fwd(cur, cur->cols / 2);
2507 		break;
2508 
2509 	case REQ_SCR_HBHALF:
2510 		_formi_hscroll_back(cur, cur->cols / 2);
2511 		break;
2512 
2513 	default:
2514 		return 0;
2515 	}
2516 
2517 #ifdef DEBUG
2518 	fprintf(dbg,
2519 	 "exit: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
2520 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
2521 		cur->buffers[0].length,	cur->buffers[0].allocated);
2522 	fprintf(dbg, "exit: start_line=%d, ypos=%d\n", cur->start_line,
2523 		cur->cursor_ypos);
2524 	fprintf(dbg, "exit: string=\"%s\"\n", cur->buffers[0].string);
2525 	assert ((cur->cursor_xpos < INT_MAX) && (cur->row_xpos < INT_MAX)
2526 		&& (cur->cursor_xpos >= cur->row_xpos));
2527 #endif
2528 	return 1;
2529 }
2530 
2531 /*
2532  * Validate the give character by passing it to any type character
2533  * checking routines, if they exist.
2534  */
2535 int
2536 _formi_validate_char(FIELD *field, char c)
2537 {
2538 	int ret_val;
2539 
2540 	if (field->type == NULL)
2541 		return E_OK;
2542 
2543 	ret_val = E_INVALID_FIELD;
2544 	_formi_do_char_validation(field, field->type, c, &ret_val);
2545 
2546 	return ret_val;
2547 }
2548 
2549 
2550 /*
2551  * Perform the validation of the character, invoke all field_type validation
2552  * routines.  If the field is ok then update ret_val to E_OK otherwise
2553  * ret_val is not changed.
2554  */
2555 static void
2556 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val)
2557 {
2558 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2559 		_formi_do_char_validation(field, type->link->next, c, ret_val);
2560 		_formi_do_char_validation(field, type->link->prev, c, ret_val);
2561 	} else {
2562 		if (type->char_check == NULL)
2563 			*ret_val = E_OK;
2564 		else {
2565 			if (type->char_check((int)(unsigned char) c,
2566 					     field->args) == TRUE)
2567 				*ret_val = E_OK;
2568 		}
2569 	}
2570 }
2571 
2572 /*
2573  * Validate the current field.  If the field validation returns success then
2574  * return E_OK otherwise return E_INVALID_FIELD.
2575  *
2576  */
2577 int
2578 _formi_validate_field(FORM *form)
2579 {
2580 	FIELD *cur;
2581 	char *bp;
2582 	int ret_val, count;
2583 
2584 
2585 	if ((form == NULL) || (form->fields == NULL) ||
2586 	    (form->fields[0] == NULL))
2587 		return E_INVALID_FIELD;
2588 
2589 	cur = form->fields[form->cur_field];
2590 
2591 	bp = cur->buffers[0].string;
2592 	count = _formi_skip_blanks(bp, 0);
2593 
2594 	  /* check if we have a null field, depending on the nullok flag
2595 	   * this may be acceptable or not....
2596 	   */
2597 	if (cur->buffers[0].string[count] == '\0') {
2598 		if ((cur->opts & O_NULLOK) == O_NULLOK)
2599 			return E_OK;
2600 		else
2601 			return E_INVALID_FIELD;
2602 	}
2603 
2604 	  /* check if an unmodified field is ok */
2605 	if (cur->buf0_status == 0) {
2606 		if ((cur->opts & O_PASSOK) == O_PASSOK)
2607 			return E_OK;
2608 		else
2609 			return E_INVALID_FIELD;
2610 	}
2611 
2612 	  /* if there is no type then just accept the field */
2613 	if (cur->type == NULL)
2614 		return E_OK;
2615 
2616 	ret_val = E_INVALID_FIELD;
2617 	_formi_do_validation(cur, cur->type, &ret_val);
2618 
2619 	return ret_val;
2620 }
2621 
2622 /*
2623  * Perform the validation of the field, invoke all field_type validation
2624  * routines.  If the field is ok then update ret_val to E_OK otherwise
2625  * ret_val is not changed.
2626  */
2627 static void
2628 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val)
2629 {
2630 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2631 		_formi_do_validation(field, type->link->next, ret_val);
2632 		_formi_do_validation(field, type->link->prev, ret_val);
2633 	} else {
2634 		if (type->field_check == NULL)
2635 			*ret_val = E_OK;
2636 		else {
2637 			if (type->field_check(field, field_buffer(field, 0))
2638 			    == TRUE)
2639 				*ret_val = E_OK;
2640 		}
2641 	}
2642 }
2643 
2644 /*
2645  * Select the next/previous choice for the field, the driver command
2646  * selecting the direction will be passed in c.  Return 1 if a choice
2647  * selection succeeded, 0 otherwise.
2648  */
2649 int
2650 _formi_field_choice(FORM *form, int c)
2651 {
2652 	FIELDTYPE *type;
2653 	FIELD *field;
2654 
2655 	if ((form == NULL) || (form->fields == NULL) ||
2656 	    (form->fields[0] == NULL) ||
2657 	    (form->fields[form->cur_field]->type == NULL))
2658 		return 0;
2659 
2660 	field = form->fields[form->cur_field];
2661 	type = field->type;
2662 
2663 	switch (c) {
2664 	case REQ_NEXT_CHOICE:
2665 		if (type->next_choice == NULL)
2666 			return 0;
2667 		else
2668 			return type->next_choice(field,
2669 						 field_buffer(field, 0));
2670 
2671 	case REQ_PREV_CHOICE:
2672 		if (type->prev_choice == NULL)
2673 			return 0;
2674 		else
2675 			return type->prev_choice(field,
2676 						 field_buffer(field, 0));
2677 
2678 	default: /* should never happen! */
2679 		return 0;
2680 	}
2681 }
2682 
2683 /*
2684  * Update the fields if they have changed.  The parameter old has the
2685  * previous current field as the current field may have been updated by
2686  * the driver.  Return 1 if the form page needs updating.
2687  *
2688  */
2689 int
2690 _formi_update_field(FORM *form, int old_field)
2691 {
2692 	int cur, i;
2693 
2694 	cur = form->cur_field;
2695 
2696 	if (old_field != cur) {
2697 		if (!((cur >= form->page_starts[form->page].first) &&
2698 		      (cur <= form->page_starts[form->page].last))) {
2699 			  /* not on same page any more */
2700 			for (i = 0; i < form->max_page; i++) {
2701 				if ((form->page_starts[i].in_use == 1) &&
2702 				    (form->page_starts[i].first <= cur) &&
2703 				    (form->page_starts[i].last >= cur)) {
2704 					form->page = i;
2705 					return 1;
2706 				}
2707 			}
2708 		}
2709 	}
2710 
2711 	_formi_redraw_field(form, old_field);
2712 	_formi_redraw_field(form, form->cur_field);
2713 	return 0;
2714 }
2715 
2716 /*
2717  * Compare function for the field sorting
2718  *
2719  */
2720 static int
2721 field_sort_compare(const void *one, const void *two)
2722 {
2723 	const FIELD *a, *b;
2724 	int tl;
2725 
2726 	  /* LINTED const castaway; we don't modify these! */
2727 	a = (const FIELD *) *((const FIELD **) one);
2728 	b = (const FIELD *) *((const FIELD **) two);
2729 
2730 	if (a == NULL)
2731 		return 1;
2732 
2733 	if (b == NULL)
2734 		return -1;
2735 
2736 	  /*
2737 	   * First check the page, we want the fields sorted by page.
2738 	   *
2739 	   */
2740 	if (a->page != b->page)
2741 		return ((a->page > b->page)? 1 : -1);
2742 
2743 	tl = _formi_top_left(a->parent, a->index, b->index);
2744 
2745 	  /*
2746 	   * sort fields left to right, top to bottom so the top left is
2747 	   * the less than value....
2748 	   */
2749 	return ((tl == a->index)? -1 : 1);
2750 }
2751 
2752 /*
2753  * Sort the fields in a form ready for driver traversal.
2754  */
2755 void
2756 _formi_sort_fields(FORM *form)
2757 {
2758 	FIELD **sort_area;
2759 	int i;
2760 
2761 	CIRCLEQ_INIT(&form->sorted_fields);
2762 
2763 	if ((sort_area = (FIELD **) malloc(sizeof(FIELD *) * form->field_count))
2764 	    == NULL)
2765 		return;
2766 
2767 	bcopy(form->fields, sort_area, sizeof(FIELD *) * form->field_count);
2768 	qsort(sort_area, (unsigned) form->field_count, sizeof(FIELD *),
2769 	      field_sort_compare);
2770 
2771 	for (i = 0; i < form->field_count; i++)
2772 		CIRCLEQ_INSERT_TAIL(&form->sorted_fields, sort_area[i], glue);
2773 
2774 	free(sort_area);
2775 }
2776 
2777 /*
2778  * Set the neighbours for all the fields in the given form.
2779  */
2780 void
2781 _formi_stitch_fields(FORM *form)
2782 {
2783 	int above_row, below_row, end_above, end_below, cur_row, real_end;
2784 	FIELD *cur, *above, *below;
2785 
2786 	  /*
2787 	   * check if the sorted fields circle queue is empty, just
2788 	   * return if it is.
2789 	   */
2790 	if (CIRCLEQ_EMPTY(&form->sorted_fields))
2791 		return;
2792 
2793 	  /* initially nothing is above..... */
2794 	above_row = -1;
2795 	end_above = TRUE;
2796 	above = NULL;
2797 
2798 	  /* set up the first field as the current... */
2799 	cur = CIRCLEQ_FIRST(&form->sorted_fields);
2800 	cur_row = cur->form_row;
2801 
2802 	  /* find the first field on the next row if any */
2803 	below = CIRCLEQ_NEXT(cur, glue);
2804 	below_row = -1;
2805 	end_below = TRUE;
2806 	real_end = TRUE;
2807 	while (below != (void *)&form->sorted_fields) {
2808 		if (below->form_row != cur_row) {
2809 			below_row = below->form_row;
2810 			end_below = FALSE;
2811 			real_end = FALSE;
2812 			break;
2813 		}
2814 		below = CIRCLEQ_NEXT(below, glue);
2815 	}
2816 
2817 	  /* walk the sorted fields, setting the neighbour pointers */
2818 	while (cur != (void *) &form->sorted_fields) {
2819 		if (cur == CIRCLEQ_FIRST(&form->sorted_fields))
2820 			cur->left = NULL;
2821 		else
2822 			cur->left = CIRCLEQ_PREV(cur, glue);
2823 
2824 		if (cur == CIRCLEQ_LAST(&form->sorted_fields))
2825 			cur->right = NULL;
2826 		else
2827 			cur->right = CIRCLEQ_NEXT(cur, glue);
2828 
2829 		if (end_above == TRUE)
2830 			cur->up = NULL;
2831 		else {
2832 			cur->up = above;
2833 			above = CIRCLEQ_NEXT(above, glue);
2834 			if (above_row != above->form_row) {
2835 				end_above = TRUE;
2836 				above_row = above->form_row;
2837 			}
2838 		}
2839 
2840 		if (end_below == TRUE)
2841 			cur->down = NULL;
2842 		else {
2843 			cur->down = below;
2844 			below = CIRCLEQ_NEXT(below, glue);
2845 			if (below == (void *) &form->sorted_fields) {
2846 				end_below = TRUE;
2847 				real_end = TRUE;
2848 			} else if (below_row != below->form_row) {
2849 				end_below = TRUE;
2850 				below_row = below->form_row;
2851 			}
2852 		}
2853 
2854 		cur = CIRCLEQ_NEXT(cur, glue);
2855 		if ((cur != (void *) &form->sorted_fields)
2856 		    && (cur_row != cur->form_row)) {
2857 			cur_row = cur->form_row;
2858 			if (end_above == FALSE) {
2859 				for (; above != CIRCLEQ_FIRST(&form->sorted_fields);
2860 				     above = CIRCLEQ_NEXT(above, glue)) {
2861 					if (above->form_row != above_row) {
2862 						above_row = above->form_row;
2863 						break;
2864 					}
2865 				}
2866 			} else if (above == NULL) {
2867 				above = CIRCLEQ_FIRST(&form->sorted_fields);
2868 				end_above = FALSE;
2869 				above_row = above->form_row;
2870 			} else
2871 				end_above = FALSE;
2872 
2873 			if (end_below == FALSE) {
2874 				while (below_row == below->form_row) {
2875 					below = CIRCLEQ_NEXT(below,
2876 							     glue);
2877 					if (below ==
2878 					    (void *)&form->sorted_fields) {
2879 						real_end = TRUE;
2880 						end_below = TRUE;
2881 						break;
2882 					}
2883 				}
2884 
2885 				if (below != (void *)&form->sorted_fields)
2886 					below_row = below->form_row;
2887 			} else if (real_end == FALSE)
2888 				end_below = FALSE;
2889 
2890 		}
2891 	}
2892 }
2893 
2894 /*
2895  * Calculate the length of the displayed line allowing for any tab
2896  * characters that need to be expanded.  We assume that the tab stops
2897  * are 8 characters apart.  The parameters start and end are the
2898  * character positions in the string str we want to get the length of,
2899  * the function returns the number of characters from the start
2900  * position to the end position that should be displayed after any
2901  * intervening tabs have been expanded.
2902  */
2903 int
2904 _formi_tab_expanded_length(char *str, unsigned int start, unsigned int end)
2905 {
2906 	int len, start_len, i;
2907 
2908 	  /* if we have a null string then there is no length */
2909 	if (str[0] == '\0')
2910 		return 0;
2911 
2912 	len = 0;
2913 	start_len = 0;
2914 
2915 	  /*
2916 	   * preceding tabs affect the length tabs in the span, so
2917 	   * we need to calculate the length including the stuff before
2918 	   * start and then subtract off the unwanted bit.
2919 	   */
2920 	for (i = 0; i <= end; i++) {
2921 		if (i == start) /* stash preamble length for later */
2922 			start_len = len;
2923 
2924 		if (str[i] == '\0')
2925 			break;
2926 
2927 		if (str[i] == '\t')
2928 			len = len - (len % 8) + 8;
2929 		else
2930 			len++;
2931 	}
2932 
2933 #ifdef DEBUG
2934 	if (dbg != NULL) {
2935 		fprintf(dbg,
2936 		    "tab_expanded: start=%d, end=%d, expanded=%d (diff=%d)\n",
2937 			start, end, (len - start_len), (end - start));
2938 	}
2939 #endif
2940 
2941 	return (len - start_len);
2942 }
2943 
2944 /*
2945  * Calculate the tab stops on a given line in the field and set up
2946  * the tabs list with the results.  We do this by scanning the line for tab
2947  * characters and if one is found, noting the position and the number of
2948  * characters to get to the next tab stop.  This information is kept to
2949  * make manipulating the field (scrolling and so on) easier to handle.
2950  */
2951 void
2952 _formi_calculate_tabs(FIELD *field, unsigned row)
2953 {
2954 	_formi_tab_t *ts = field->lines[row].tabs, *old_ts = NULL, **tsp;
2955 	int i, j;
2956 
2957 	  /*
2958 	   * If the line already has tabs then invalidate them by
2959 	   * walking the list and killing the in_use flag.
2960 	   */
2961 	for (; ts != NULL; ts = ts->fwd)
2962 		ts->in_use = FALSE;
2963 
2964 
2965 	  /*
2966 	   * Now look for tabs in the row and record the info...
2967 	   */
2968 	tsp = &field->lines[row].tabs;
2969 	for (i = field->lines[row].start, j = 0; i <= field->lines[row].end;
2970 	     i++, j++) {
2971 		if (field->buffers[0].string[i] == '\t') {
2972 			if (*tsp == NULL) {
2973 				if ((*tsp = (_formi_tab_t *)
2974 				     malloc(sizeof(_formi_tab_t))) == NULL)
2975 					return;
2976 				(*tsp)->back = old_ts;
2977 				(*tsp)->fwd = NULL;
2978 			}
2979 
2980 			(*tsp)->in_use = TRUE;
2981 			(*tsp)->pos = i - field->lines[row].start;
2982 			(*tsp)->size = 8 - (j % 8);
2983 			j += (*tsp)->size - 1;
2984 			old_ts = *tsp;
2985 			tsp = &(*tsp)->fwd;
2986 		}
2987 	}
2988 }
2989 
2990 /*
2991  * Return the size of the tab padding for a tab character at the given
2992  * position.  Return 1 if there is not a tab char entry matching the
2993  * given location.
2994  */
2995 static int
2996 tab_size(FIELD *field, unsigned int offset, unsigned int i)
2997 {
2998 	int row;
2999 	_formi_tab_t *ts;
3000 
3001 	row = find_cur_line(field, offset + i);
3002 	ts = field->lines[row].tabs;
3003 
3004 	while ((ts != NULL) && (ts->pos != i))
3005 		ts = ts->fwd;
3006 
3007 	if (ts == NULL)
3008 		return 1;
3009 	else
3010 		return ts->size;
3011 }
3012 
3013 /*
3014  * Find the character offset that corresponds to longest tab expanded
3015  * string that will fit into the given window.  Walk the string backwards
3016  * evaluating the sizes of any tabs that are in the string.  Note that
3017  * using this function on a multi-line window will produce undefined
3018  * results - it is really only required for a single row field.
3019  */
3020 static int
3021 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window)
3022 {
3023 	int scroll_amt, i;
3024 	_formi_tab_t *ts;
3025 
3026 	  /* first find the last tab */
3027 	ts = field->lines[0].tabs;
3028 
3029 	  /*
3030 	   * unless there are no tabs - just return the window size,
3031 	   * if there is enough room, otherwise 0.
3032 	   */
3033 	if (ts == NULL) {
3034 		if (field->buffers[0].length < window)
3035 			return 0;
3036 		else
3037 			return field->buffers[0].length - window + 1;
3038 	}
3039 
3040 	while ((ts->fwd != NULL) && (ts->fwd->in_use == TRUE))
3041 		ts = ts->fwd;
3042 
3043 	  /*
3044 	   * now walk backwards finding the first tab that is to the
3045 	   * left of our starting pos.
3046 	   */
3047 	while ((ts != NULL) && (ts->in_use == TRUE) && (ts->pos > pos))
3048 		ts = ts->back;
3049 
3050 	scroll_amt = 0;
3051 	for (i = pos; i >= 0; i--) {
3052 		if (field->buffers[0].string[i] == '\t') {
3053 #ifdef DEBUG
3054 			assert((ts != NULL) && (ts->in_use == TRUE));
3055 #endif
3056 			if (ts->pos == i) {
3057 				if ((scroll_amt + ts->size) > window) {
3058 					break;
3059 				}
3060 				scroll_amt += ts->size;
3061 				ts = ts->back;
3062 			}
3063 #ifdef DEBUG
3064 			else
3065 				assert(ts->pos == i);
3066 #endif
3067 		} else {
3068 			scroll_amt++;
3069 			if (scroll_amt > window)
3070 				break;
3071 		}
3072 	}
3073 
3074 	return ++i;
3075 }
3076 
3077 /*
3078  * Return the position of the last character that will fit into the
3079  * given width after tabs have been expanded for a given row of a given
3080  * field.
3081  */
3082 static unsigned int
3083 tab_fit_len(FIELD *field, unsigned int row, unsigned int width)
3084 {
3085 	unsigned int pos, len, row_pos;
3086 	_formi_tab_t *ts;
3087 
3088 	ts = field->lines[row].tabs;
3089 	pos = field->lines[row].start;
3090 	len = 0;
3091 	row_pos = 0;
3092 
3093 	while ((len < width) && (pos < field->buffers[0].length)) {
3094 		if (field->buffers[0].string[pos] == '\t') {
3095 #ifdef DEBUG
3096 			assert((ts != NULL) && (ts->in_use == TRUE));
3097 #endif
3098 			if (ts->pos == row_pos) {
3099 				if ((len + ts->size) > width)
3100 					break;
3101 				len += ts->size;
3102 				ts = ts->fwd;
3103 			}
3104 #ifdef DEBUG
3105 			else
3106 				assert(ts->pos == row_pos);
3107 #endif
3108 		} else
3109 			len++;
3110 		pos++;
3111 		row_pos++;
3112 	}
3113 
3114 	if (pos > 0)
3115 		pos--;
3116 	return pos;
3117 }
3118