xref: /netbsd/lib/libform/internals.c (revision bf9ec67e)
1 /*	$NetBSD: internals.c,v 1.23 2002/05/20 15:00:11 blymn Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998-1999 Brett Lymn
5  *                         (blymn@baea.com.au, brett_lymn@yahoo.com.au)
6  * All rights reserved.
7  *
8  * This code has been donated to The NetBSD Foundation by the Author.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. The name of the author may not be used to endorse or promote products
16  *    derived from this software 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 <limits.h>
33 #include <ctype.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <strings.h>
37 #include <assert.h>
38 #include "internals.h"
39 #include "form.h"
40 
41 #ifdef DEBUG
42 /*
43  *  file handle to write debug info to, this will be initialised when
44  *  the form is first posted.
45  */
46 FILE *dbg = NULL;
47 
48 /*
49  * map the request numbers to strings for debug
50  */
51 char *reqs[] = {
52 	"NEXT_PAGE", "PREV_PAGE", "FIRST_PAGE",	"LAST_PAGE", "NEXT_FIELD",
53 	"PREV_FIELD", "FIRST_FIELD", "LAST_FIELD", "SNEXT_FIELD",
54 	"SPREV_FIELD", "SFIRST_FIELD", "SLAST_FIELD", "LEFT_FIELD",
55 	"RIGHT_FIELD", "UP_FIELD", "DOWN_FIELD", "NEXT_CHAR", "PREV_CHAR",
56 	"NEXT_LINE", "PREV_LINE", "NEXT_WORD", "PREV_WORD", "BEG_FIELD",
57 	"END_FIELD", "BEG_LINE", "END_LINE", "LEFT_CHAR", "RIGHT_CHAR",
58 	"UP_CHAR", "DOWN_CHAR", "NEW_LINE", "INS_CHAR", "INS_LINE",
59 	"DEL_CHAR", "DEL_PREV", "DEL_LINE", "DEL_WORD", "CLR_EOL",
60 	"CLR_EOF", "CLR_FIELD", "OVL_MODE", "INS_MODE", "SCR_FLINE",
61 	"SCR_BLINE", "SCR_FPAGE", "SCR_BPAGE", "SCR_FHPAGE", "SCR_BHPAGE",
62 	"SCR_FCHAR", "SCR_BCHAR", "SCR_HFLINE", "SCR_HBLINE", "SCR_HFHALF",
63 	"SCR_HBHALF", "VALIDATION", "PREV_CHOICE", "NEXT_CHOICE" };
64 #endif
65 
66 /* define our own min function - this is not generic but will do here
67  * (don't believe me?  think about what value you would get
68  * from min(x++, y++)
69  */
70 #define min(a,b) (((a) > (b))? (b) : (a))
71 
72 /* for the line joining function... */
73 #define JOIN_NEXT    1
74 #define JOIN_NEXT_NW 2 /* next join, don't wrap the joined line */
75 #define JOIN_PREV    3
76 #define JOIN_PREV_NW 4 /* previous join, don't wrap the joined line */
77 
78 /* for the bump_lines function... */
79 #define _FORMI_USE_CURRENT -1 /* indicates current cursor pos to be used */
80 
81 static void
82 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val);
83 static void
84 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val);
85 static int
86 _formi_join_line(FIELD *field, unsigned int pos, int direction);
87 void
88 _formi_hscroll_back(FIELD *field, unsigned int amt);
89 void
90 _formi_hscroll_fwd(FIELD *field, unsigned int amt);
91 static void
92 _formi_scroll_back(FIELD *field, unsigned int amt);
93 static void
94 _formi_scroll_fwd(FIELD *field, unsigned int amt);
95 static int
96 find_sow(char *str, unsigned int offset);
97 static int
98 find_cur_line(FIELD *cur, unsigned pos);
99 static int
100 split_line(FIELD *field, unsigned pos);
101 static void
102 bump_lines(FIELD *field, int pos, int amt, bool do_len);
103 static bool
104 check_field_size(FIELD *field);
105 static int
106 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c);
107 static int
108 tab_size(FIELD *field, unsigned int offset, unsigned int i);
109 static unsigned int
110 tab_fit_len(FIELD *field, unsigned int row, unsigned int len);
111 static int
112 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window);
113 
114 
115 /*
116  * Open the debug file if it is not already open....
117  */
118 #ifdef DEBUG
119 int
120 _formi_create_dbg_file(void)
121 {
122 	if (dbg == NULL) {
123 		dbg = fopen("___form_dbg.out", "w");
124 		if (dbg == NULL) {
125 			fprintf(stderr, "Cannot open debug file!\n");
126 			return E_SYSTEM_ERROR;
127 		}
128 	}
129 
130 	return E_OK;
131 }
132 #endif
133 
134 /*
135  * Bump the lines array elements in the given field by the given amount.
136  * The row to start acting on can either be inferred from the given position
137  * or if the special value _FORMI_USE_CURRENT is set then the row will be
138  * the row the cursor is currently on.
139  */
140 static void
141 bump_lines(FIELD *field, int pos, int amt, bool do_len)
142 {
143 	int i, row, old_len;
144 #ifdef DEBUG
145 	int dbg_ok = FALSE;
146 #endif
147 
148 	if (pos == _FORMI_USE_CURRENT)
149 		row = field->start_line + field->cursor_ypos;
150 	else
151 		row = find_cur_line(field, (unsigned) pos);
152 
153 #ifdef DEBUG
154 	if (_formi_create_dbg_file() == E_OK) {
155 		dbg_ok = TRUE;
156 		fprintf(dbg, "bump_lines: bump starting at row %d\n", row);
157 		fprintf(dbg,
158 			"bump_lines: len from %d to %d, end from %d to %d\n",
159 			field->lines[row].length,
160 			field->lines[row].length + amt,
161 			field->lines[row].end, field->lines[row].end + amt);
162 	}
163 #endif
164 
165 	if (((int)field->lines[row].length + amt) < 0) {
166 		field->lines[row].length = 0;
167 		old_len = 0;
168 	} else {
169 		old_len = field->lines[row].length;
170 		if (do_len == TRUE) {
171 			field->lines[row].length =
172 				_formi_tab_expanded_length(
173 					&field->buffers[0].string[
174 						field->lines[row].start], 0,
175 					field->lines[row].end + amt
176 					    -field->lines[row].start);
177 		}
178 	}
179 
180 	if (old_len > 0) {
181 		if ((amt < 0) && (- amt > field->lines[row].end))
182 			field->lines[row].end = field->lines[row].start;
183 		else
184 			field->lines[row].end += amt;
185 	} else
186 		field->lines[row].end = field->lines[row].start;
187 
188 #ifdef DEBUG
189 	if (dbg_ok)
190 		fprintf(dbg, "bump_lines: expanded length %d\n",
191 			field->lines[row].length);
192 #endif
193 
194 	for (i = row + 1; i < field->row_count; i++) {
195 #ifdef DEBUG
196 		if (dbg_ok) {
197 			fprintf(dbg,
198 		"bump_lines: row %d: len from %d to %d, end from %d to %d\n",
199 				i, field->lines[i].start,
200 				field->lines[i].start + amt,
201 				field->lines[i].end,
202 				field->lines[i].end + amt);
203 		}
204 		fflush(dbg);
205 #endif
206 		field->lines[i].start += amt;
207 		field->lines[i].end += amt;
208 		field->lines[i].length = _formi_tab_expanded_length(
209 			&field->buffers[0].string[field->lines[i].start],
210 			0, field->lines[i].end - field->lines[i].start);
211 #ifdef DEBUG
212 		if (dbg_ok) {
213 			fprintf(dbg,
214 				"bump_lines: row %d, expanded length %d\n",
215 				i, field->lines[i].length);
216 		}
217 #endif
218 	}
219 }
220 
221 /*
222  * Check the sizing of the field, if the maximum size is set for a
223  * dynamic field then check that the number of rows or columns does
224  * not exceed the set maximum.  The decision to check the rows or
225  * columns is made on the basis of how many rows are in the field -
226  * one row means the max applies to the number of columns otherwise it
227  * applies to the number of rows.  If the row/column count is less
228  * than the maximum then return TRUE.
229  *
230  */
231 static bool
232 check_field_size(FIELD *field)
233 {
234 	if ((field->opts & O_STATIC) != O_STATIC) {
235 		  /* dynamic field */
236 		if (field->max == 0) /* unlimited */
237 			return TRUE;
238 
239 		if (field->rows == 1) {
240 			return (field->buffers[0].length < field->max);
241 		} else {
242 			return (field->row_count <= field->max);
243 		}
244 	} else {
245 		if ((field->rows + field->nrows) == 1) {
246 			return (field->buffers[0].length <= field->cols);
247 		} else {
248 			return (field->row_count <= (field->rows
249 						     + field->nrows));
250 		}
251 	}
252 }
253 
254 /*
255  * Set the form's current field to the first valid field on the page.
256  * Assume the fields have been sorted and stitched.
257  */
258 int
259 _formi_pos_first_field(FORM *form)
260 {
261 	FIELD *cur;
262 	int old_page;
263 
264 	old_page = form->page;
265 
266 	  /* scan forward for an active page....*/
267 	while (form->page_starts[form->page].in_use == 0) {
268 		form->page++;
269 		if (form->page > form->max_page) {
270 			form->page = old_page;
271 			return E_REQUEST_DENIED;
272 		}
273 	}
274 
275 	  /* then scan for a field we can use */
276 	cur = form->fields[form->page_starts[form->page].first];
277 	while ((cur->opts & (O_VISIBLE | O_ACTIVE))
278 	       != (O_VISIBLE | O_ACTIVE)) {
279 		cur = CIRCLEQ_NEXT(cur, glue);
280 		if (cur == (void *) &form->sorted_fields) {
281 			form->page = old_page;
282 			return E_REQUEST_DENIED;
283 		}
284 	}
285 
286 	form->cur_field = cur->index;
287 	return E_OK;
288 }
289 
290 /*
291  * Set the field to the next active and visible field, the fields are
292  * traversed in index order in the direction given.  If the parameter
293  * use_sorted is TRUE then the sorted field list will be traversed instead
294  * of using the field index.
295  */
296 int
297 _formi_pos_new_field(FORM *form, unsigned direction, unsigned use_sorted)
298 {
299 	FIELD *cur;
300 	int i;
301 
302 	i = form->cur_field;
303 	cur = form->fields[i];
304 
305 	do {
306 		if (direction == _FORMI_FORWARD) {
307 			if (use_sorted == TRUE) {
308 				if ((form->wrap == FALSE) &&
309 				    (cur == CIRCLEQ_LAST(&form->sorted_fields)))
310 					return E_REQUEST_DENIED;
311 				cur = CIRCLEQ_NEXT(cur, glue);
312 				i = cur->index;
313 			} else {
314 				if ((form->wrap == FALSE) &&
315 				    ((i + 1) >= form->field_count))
316 					return E_REQUEST_DENIED;
317 				i++;
318 				if (i >= form->field_count)
319 					i = 0;
320 			}
321 		} else {
322 			if (use_sorted == TRUE) {
323 				if ((form->wrap == FALSE) &&
324 				    (cur == CIRCLEQ_FIRST(&form->sorted_fields)))
325 					return E_REQUEST_DENIED;
326 				cur = CIRCLEQ_PREV(cur, glue);
327 				i = cur->index;
328 			} else {
329 				if ((form->wrap == FALSE) && (i <= 0))
330 					return E_REQUEST_DENIED;
331 				i--;
332 				if (i < 0)
333 					i = form->field_count - 1;
334 			}
335 		}
336 
337 		if ((form->fields[i]->opts & (O_VISIBLE | O_ACTIVE))
338 			== (O_VISIBLE | O_ACTIVE)) {
339 			form->cur_field = i;
340 			return E_OK;
341 		}
342 	}
343 	while (i != form->cur_field);
344 
345 	return E_REQUEST_DENIED;
346 }
347 
348 /*
349  * Find the line in a field that the cursor is currently on.
350  */
351 static int
352 find_cur_line(FIELD *cur, unsigned pos)
353 {
354 	unsigned row;
355 
356 	  /* if there is only one row then that must be it */
357 	if (cur->row_count == 1)
358 		return 0;
359 
360 	  /* first check if pos is at the end of the string, if this
361 	   * is true then just return the last row since the pos may
362 	   * not have been added to the lines array yet.
363 	   */
364 	if (pos == (cur->buffers[0].length - 1))
365 		return (cur->row_count - 1);
366 
367 	for (row = 0; row < cur->row_count; row++) {
368 		if ((pos >= cur->lines[row].start)
369 		    && (pos <= cur->lines[row].end))
370 			return row;
371 	}
372 
373 #ifdef DEBUG
374 	  /* barf if we get here, this should not be possible */
375 	assert((row != row));
376 #endif
377 	return 0;
378 }
379 
380 
381 /*
382  * Word wrap the contents of the field's buffer 0 if this is allowed.
383  * If the wrap is successful, that is, the row count nor the buffer
384  * size is exceeded then the function will return E_OK, otherwise it
385  * will return E_REQUEST_DENIED.
386  */
387 int
388 _formi_wrap_field(FIELD *field, unsigned int loc)
389 {
390 	char *str;
391 	int width, row, start_row;
392 	unsigned int pos;
393 
394 	str = field->buffers[0].string;
395 
396 	if ((field->opts & O_STATIC) == O_STATIC) {
397 		if ((field->rows + field->nrows) == 1) {
398 			return E_OK; /* cannot wrap a single line */
399 		}
400 		width = field->cols;
401 	} else {
402 		  /* if we are limited to one line then don't try to wrap */
403 		if ((field->drows + field->nrows) == 1) {
404 			return E_OK;
405 		}
406 
407 		  /*
408 		   * hueristic - if a dynamic field has more than one line
409 		   * on the screen then the field grows rows, otherwise
410 		   * it grows columns, effectively a single line field.
411 		   * This is documented AT&T behaviour.
412 		   */
413 		if (field->rows > 1) {
414 			width = field->cols;
415 		} else {
416 			return E_OK;
417 		}
418 	}
419 
420 	start_row = find_cur_line(field, loc);
421 
422 	  /* if we are not at the top of the field then back up one
423 	   * row because we may be able to merge the current row into
424 	   * the one above.
425 	   */
426 	if (start_row > 0)
427 		start_row--;
428 
429 	for (row = start_row; row < field->row_count; row++) {
430 	  AGAIN:
431 		pos = field->lines[row].end;
432 		if (field->lines[row].length < width) {
433 			  /* line may be too short, try joining some lines */
434 
435 			if ((((int) field->row_count) - 1) == row) {
436 				/* if this is the last row then don't
437 				 * wrap
438 				 */
439 				continue;
440 			}
441 
442 			if (_formi_join_line(field, (unsigned int) pos,
443 					     JOIN_NEXT_NW) == E_OK) {
444 				goto AGAIN;
445 			} else
446 				break;
447 		} else {
448 			  /* line is too long, split it - maybe */
449 
450 			  /* first check if we have not run out of room */
451 			if ((field->opts & O_STATIC) == O_STATIC) {
452 				/* check static field */
453 				if ((field->rows + field->nrows - 1) == row)
454 					return E_REQUEST_DENIED;
455 			} else {
456 				/* check dynamic field */
457 				if ((field->max != 0)
458 				    && ((field->max - 1) == row))
459 					return E_REQUEST_DENIED;
460 			}
461 
462 			  /*
463 			   * split on first whitespace before current word
464 			   * if the line has tabs we need to work out where
465 			   * the field border lies when the tabs are expanded.
466 			   */
467 			if (field->lines[row].tabs == NULL) {
468 				pos = width + field->lines[row].start - 1;
469 				if (pos >= field->buffers[0].length)
470 					pos = field->buffers[0].length - 1;
471 			} else {
472 				pos = tab_fit_len(field, (unsigned) row,
473 						  field->cols);
474 			}
475 
476 
477 			if ((!isblank(str[pos])) &&
478 			    ((field->opts & O_WRAP) == O_WRAP)) {
479 				if (!isblank(str[pos - 1]))
480 					pos = find_sow(str,
481 						       (unsigned int) pos);
482 				/*
483 				 * If we cannot split the line then return
484 				 * NO_ROOM so the driver can tell that it
485 				 * should not autoskip (if that is enabled)
486 				 */
487 				if ((pos == 0) || (!isblank(str[pos - 1]))
488 				    || ((pos <= field->lines[row].start)
489 					&& (field->buffers[0].length
490 					    >= (width - 1
491 						+ field->lines[row].start)))) {
492 					return E_NO_ROOM;
493 				}
494 			}
495 
496 			  /* if we are at the end of the string and it has
497 			   * a trailing blank, don't wrap the blank.
498 			   */
499 			if ((pos == field->buffers[0].length - 1) &&
500 			    (isblank(str[pos])) &&
501 			    field->lines[row].length <= field->cols)
502 				continue;
503 
504 			  /*
505 			   * otherwise, if we are still sitting on a
506 			   * blank but not at the end of the line
507 			   * move forward one char so the blank
508 			   * is on the line boundary.
509 			   */
510 			if ((isblank(str[pos])) &&
511 			    (pos != field->buffers[0].length - 1))
512 				pos++;
513 
514 			if (split_line(field, pos) != E_OK) {
515 				return E_REQUEST_DENIED;
516 			}
517 		}
518 	}
519 
520 	return E_OK;
521 }
522 
523 /*
524  * Join the two lines that surround the location pos, the type
525  * variable indicates the direction of the join, JOIN_NEXT will join
526  * the next line to the current line, JOIN_PREV will join the current
527  * line to the previous line, the new lines will be wrapped unless the
528  * _NW versions of the directions are used.  Returns E_OK if the join
529  * was successful or E_REQUEST_DENIED if the join cannot happen.
530  */
531 static int
532 _formi_join_line(FIELD *field, unsigned int pos, int direction)
533 {
534 	unsigned int row, i;
535 	int old_alloced, old_row_count;
536 	struct _formi_field_lines *saved;
537 #ifdef DEBUG
538 	int dbg_ok = FALSE;
539 
540 	if (_formi_create_dbg_file() == E_OK) {
541 		dbg_ok = TRUE;
542 	}
543 #endif
544 
545 	if ((saved = (struct _formi_field_lines *)
546 	     malloc(field->lines_alloced * sizeof(struct _formi_field_lines)))
547 	    == NULL)
548 		return E_REQUEST_DENIED;
549 
550 	bcopy(field->lines, saved,
551 	      field->row_count * sizeof(struct _formi_field_lines));
552 	old_alloced = field->lines_alloced;
553 	old_row_count = field->row_count;
554 
555 	row = find_cur_line(field, pos);
556 
557 #ifdef DEBUG
558 	if (dbg_ok == TRUE) {
559 		fprintf(dbg, "join_line: working on row %d, row_count = %d\n",
560 			row, field->row_count);
561 	}
562 #endif
563 
564 	if ((direction == JOIN_NEXT) || (direction == JOIN_NEXT_NW)) {
565 		  /* see if there is another line following... */
566 		if (row == (field->row_count - 1)) {
567 			free(saved);
568 			return E_REQUEST_DENIED;
569 		}
570 
571 #ifdef DEBUG
572 		if (dbg_ok == TRUE) {
573 			fprintf(dbg,
574 			"join_line: join_next before end = %d, length = %d",
575 				field->lines[row].end,
576 				field->lines[row].length);
577 			fprintf(dbg,
578 				" :: next row end = %d, length = %d\n",
579 				field->lines[row + 1].end,
580 				field->lines[row + 1].length);
581 		}
582 #endif
583 
584 		field->lines[row].end = field->lines[row + 1].end;
585 		field->lines[row].length =
586 			_formi_tab_expanded_length(field->buffers[0].string,
587 					    field->lines[row].start,
588 					    field->lines[row].end);
589 		_formi_calculate_tabs(field, row);
590 
591 		  /* shift all the remaining lines up.... */
592 		for (i = row + 2; i < field->row_count; i++)
593 			field->lines[i - 1] = field->lines[i];
594 	} else {
595 		if ((pos == 0) || (row == 0)) {
596 			free(saved);
597 			return E_REQUEST_DENIED;
598 		}
599 
600 #ifdef DEBUG
601 		if (dbg_ok == TRUE) {
602 			fprintf(dbg,
603 			"join_line: join_prev before end = %d, length = %d",
604 				field->lines[row].end,
605 				field->lines[row].length);
606 			fprintf(dbg,
607 				" :: prev row end = %d, length = %d\n",
608 				field->lines[row - 1].end,
609 				field->lines[row - 1].length);
610 		}
611 #endif
612 
613 		field->lines[row - 1].end = field->lines[row].end;
614 		field->lines[row - 1].length =
615 			_formi_tab_expanded_length(field->buffers[0].string,
616 					    field->lines[row - 1].start,
617 					    field->lines[row].end);
618 		  /* shift all the remaining lines up */
619 		for (i = row + 1; i < field->row_count; i++)
620 			field->lines[i - 1] = field->lines[i];
621 	}
622 
623 #ifdef DEBUG
624 	if (dbg_ok == TRUE) {
625 		fprintf(dbg,
626 			"join_line: exit end = %d, length = %d\n",
627 			field->lines[row].end, field->lines[row].length);
628 	}
629 #endif
630 
631 	field->row_count--;
632 
633 	  /* wrap the field if required, if this fails undo the change */
634 	if ((direction == JOIN_NEXT) || (direction == JOIN_PREV)) {
635 		if (_formi_wrap_field(field, (unsigned int) pos) != E_OK) {
636 			free(field->lines);
637 			field->lines = saved;
638 			field->lines_alloced = old_alloced;
639 			field->row_count = old_row_count;
640 			for (i = 0; i < field->row_count; i++)
641 				_formi_calculate_tabs(field, i);
642 			return E_REQUEST_DENIED;
643 		}
644 	}
645 
646 	free(saved);
647 	return E_OK;
648 }
649 
650 /*
651  * Split the line at the given position, if possible
652  */
653 static int
654 split_line(FIELD *field, unsigned pos)
655 {
656 	struct _formi_field_lines *new_lines;
657 	unsigned int row, i;
658 #ifdef DEBUG
659 	short dbg_ok = FALSE;
660 #endif
661 
662 	if (pos == 0)
663 		return E_REQUEST_DENIED;
664 
665 #ifdef DEBUG
666 	if (_formi_create_dbg_file() == E_OK) {
667 		fprintf(dbg, "split_line: splitting line at %d\n", pos);
668 		dbg_ok = TRUE;
669 	}
670 #endif
671 
672 	if ((field->row_count + 1) > field->lines_alloced) {
673 		if ((new_lines = (struct _formi_field_lines *)
674 		     realloc(field->lines, (field->row_count + 1)
675 			     * sizeof(struct _formi_field_lines))) == NULL)
676 			return E_SYSTEM_ERROR;
677 		field->lines = new_lines;
678 		field->lines_alloced++;
679 	}
680 
681 	row = find_cur_line(field, pos);
682 #ifdef DEBUG
683 	if (dbg_ok == TRUE) {
684 		fprintf(dbg,
685 	"split_line: enter: lines[%d].end = %d, lines[%d].length = %d\n",
686 			row, field->lines[row].end, row,
687 			field->lines[row].length);
688 	}
689 
690 	assert(((field->lines[row].end < INT_MAX) &&
691 		(field->lines[row].length < INT_MAX) &&
692 		(field->lines[row].length > 0)));
693 
694 #endif
695 
696 	  /* if asked to split right where the line already starts then
697 	   * just return - nothing to do.
698 	   */
699 	if (field->lines[row].start == pos)
700 		return E_OK;
701 
702 	for (i = field->row_count - 1; i > row; i--) {
703 		field->lines[i + 1] = field->lines[i];
704 	}
705 
706 	field->lines[row + 1].end = field->lines[row].end;
707 	field->lines[row].end = pos - 1;
708 	field->lines[row].length =
709 		_formi_tab_expanded_length(field->buffers[0].string,
710 				    field->lines[row].start,
711 				    field->lines[row].end);
712 	_formi_calculate_tabs(field, row);
713 	field->lines[row + 1].start = pos;
714 	field->lines[row + 1].length =
715 		_formi_tab_expanded_length(field->buffers[0].string,
716 				    field->lines[row + 1].start,
717 				    field->lines[row + 1].end);
718 	field->lines[row + 1].tabs = NULL;
719 	_formi_calculate_tabs(field, row + 1);
720 
721 #ifdef DEBUG
722 	assert(((field->lines[row + 1].end < INT_MAX) &&
723 		(field->lines[row].end < INT_MAX) &&
724 		(field->lines[row].length < INT_MAX) &&
725 		(field->lines[row + 1].start < INT_MAX) &&
726 		(field->lines[row + 1].length < INT_MAX) &&
727 		(field->lines[row].length > 0) &&
728 		(field->lines[row + 1].length > 0)));
729 
730 	if (dbg_ok == TRUE) {
731 		fprintf(dbg,
732 	"split_line: exit: lines[%d].end = %d, lines[%d].length = %d, ",
733 			row, field->lines[row].end, row,
734 			field->lines[row].length);
735 		fprintf(dbg, "lines[%d].start = %d, lines[%d].end = %d, ",
736 			row + 1, field->lines[row + 1].start, row + 1,
737 			field->lines[row + 1].end);
738 		fprintf(dbg, "lines[%d].length = %d, row_count = %d\n",
739 			row + 1, field->lines[row + 1].length,
740 			field->row_count + 1);
741 	}
742 #endif
743 
744 	field->row_count++;
745 
746 #ifdef DEBUG
747 	if (dbg_ok == TRUE) {
748 		bump_lines(field, 0, 0, FALSE); /* will report line data for us */
749 	}
750 #endif
751 
752 	return E_OK;
753 }
754 
755 /*
756  * skip the blanks in the given string, start at the index start and
757  * continue forward until either the end of the string or a non-blank
758  * character is found.  Return the index of either the end of the string or
759  * the first non-blank character.
760  */
761 unsigned
762 _formi_skip_blanks(char *string, unsigned int start)
763 {
764 	unsigned int i;
765 
766 	i = start;
767 
768 	while ((string[i] != '\0') && isblank(string[i]))
769 		i++;
770 
771 	return i;
772 }
773 
774 /*
775  * Return the index of the top left most field of the two given fields.
776  */
777 static int
778 _formi_top_left(FORM *form, int a, int b)
779 {
780 	  /* lower row numbers always win here.... */
781 	if (form->fields[a]->form_row < form->fields[b]->form_row)
782 		return a;
783 
784 	if (form->fields[a]->form_row > form->fields[b]->form_row)
785 		return b;
786 
787 	  /* rows must be equal, check columns */
788 	if (form->fields[a]->form_col < form->fields[b]->form_col)
789 		return a;
790 
791 	if (form->fields[a]->form_col > form->fields[b]->form_col)
792 		return b;
793 
794 	  /* if we get here fields must be in exactly the same place, punt */
795 	return a;
796 }
797 
798 /*
799  * Return the index to the field that is the bottom-right-most of the
800  * two given fields.
801  */
802 static int
803 _formi_bottom_right(FORM *form, int a, int b)
804 {
805 	  /* check the rows first, biggest row wins */
806 	if (form->fields[a]->form_row > form->fields[b]->form_row)
807 		return a;
808 	if (form->fields[a]->form_row < form->fields[b]->form_row)
809 		return b;
810 
811 	  /* rows must be equal, check cols, biggest wins */
812 	if (form->fields[a]->form_col > form->fields[b]->form_col)
813 		return a;
814 	if (form->fields[a]->form_col < form->fields[b]->form_col)
815 		return b;
816 
817 	  /* fields in the same place, punt */
818 	return a;
819 }
820 
821 /*
822  * Find the end of the current word in the string str, starting at
823  * offset - the end includes any trailing whitespace.  If the end of
824  * the string is found before a new word then just return the offset
825  * to the end of the string.
826  */
827 static int
828 find_eow(char *str, unsigned int offset)
829 {
830 	int start;
831 
832 	start = offset;
833 	  /* first skip any non-whitespace */
834 	while ((str[start] != '\0') && !isblank(str[start]))
835 		start++;
836 
837 	  /* see if we hit the end of the string */
838 	if (str[start] == '\0')
839 		return start;
840 
841 	  /* otherwise skip the whitespace.... */
842 	while ((str[start] != '\0') && isblank(str[start]))
843 		start++;
844 
845 	return start;
846 }
847 
848 /*
849  * Find the beginning of the current word in the string str, starting
850  * at offset.
851  */
852 static int
853 find_sow(char *str, unsigned int offset)
854 {
855 	int start;
856 
857 	start = offset;
858 
859 	if (start > 0) {
860 		if (isblank(str[start]) || isblank(str[start - 1])) {
861 			if (isblank(str[start - 1]))
862 				start--;
863 			  /* skip the whitespace.... */
864 			while ((start >= 0) && isblank(str[start]))
865 				start--;
866 		}
867 	}
868 
869 	  /* see if we hit the start of the string */
870 	if (start < 0)
871 		return 0;
872 
873 	  /* now skip any non-whitespace */
874 	while ((start >= 0) && !isblank(str[start]))
875 		start--;
876 
877 	if (start > 0)
878 		start++; /* last loop has us pointing at a space, adjust */
879 
880 	if (start < 0)
881 		start = 0;
882 
883 	return start;
884 }
885 
886 /*
887  * Scroll the field forward the given number of lines.
888  */
889 static void
890 _formi_scroll_fwd(FIELD *field, unsigned int amt)
891 {
892 	  /* check if we have lines to scroll */
893 	if (field->row_count < (field->start_line + field->rows))
894 		return;
895 
896 	field->start_line += min(amt,
897 				 field->row_count - field->start_line
898 				 - field->rows);
899 }
900 
901 /*
902  * Scroll the field backward the given number of lines.
903  */
904 static void
905 _formi_scroll_back(FIELD *field, unsigned int amt)
906 {
907 	if (field->start_line == 0)
908 		return;
909 
910 	field->start_line -= min(field->start_line, amt);
911 }
912 
913 /*
914  * Scroll the field forward the given number of characters.
915  */
916 void
917 _formi_hscroll_fwd(FIELD *field, int unsigned amt)
918 {
919 	unsigned int row, end, scroll_amt, expanded;
920 	_formi_tab_t *ts;
921 
922 	row = field->start_line + field->cursor_ypos;
923 
924 	if ((field->lines[row].tabs == NULL)
925 	    || (field->lines[row].tabs->in_use == FALSE)) {
926 		  /* if the line has no tabs things are easy... */
927 		end =  field->start_char + field->cols + amt - 1;
928 		scroll_amt = amt;
929 		if (end > field->lines[row].end) {
930 			end = field->lines[row].end;
931 			scroll_amt = end - field->start_char - field->cols + 1;
932 		}
933 	} else {
934 		  /*
935 		   * If there are tabs we need to add on the scroll amount,
936 		   * find the last char position that will fit into
937 		   * the field and finally fix up the start_char.  This
938 		   * is a lot of work but handling the case where there
939 		   * are not enough chars to scroll by amt is difficult.
940 		   */
941 		end = field->start_char + field->row_xpos + amt;
942 		if (end >= field->buffers[0].length)
943 			end = field->buffers[0].length - 1;
944 		else {
945 			expanded = _formi_tab_expanded_length(
946 				field->buffers[0].string,
947 				field->start_char + amt,
948 				field->start_char + field->row_xpos + amt);
949 			ts = field->lines[0].tabs;
950 			  /* skip tabs to the lhs of our starting point */
951 			while ((ts != NULL) && (ts->in_use == TRUE)
952 			       && (ts->pos < end))
953 				ts = ts->fwd;
954 
955 			while ((expanded <= field->cols)
956 			       && (end < field->buffers[0].length)) {
957 				if (field->buffers[0].string[end] == '\t') {
958 #ifdef DEBUG
959 					assert((ts != NULL)
960 					       && (ts->in_use == TRUE));
961 #endif
962 					if (ts->pos == end) {
963 						if ((expanded + ts->size)
964 						    > field->cols)
965 							break;
966 						expanded += ts->size;
967 						ts = ts->fwd;
968 					}
969 #ifdef DEBUG
970 					else
971 						assert(ts->pos == end);
972 #endif
973 				} else
974 					expanded++;
975 				end++;
976 			}
977 		}
978 
979 		scroll_amt = tab_fit_window(field, end, field->cols);
980 		if (scroll_amt < field->start_char)
981 			scroll_amt = 1;
982 		else
983 			scroll_amt -= field->start_char;
984 
985 		scroll_amt = min(scroll_amt, amt);
986 	}
987 
988 	field->start_char += scroll_amt;
989 	field->cursor_xpos =
990 		_formi_tab_expanded_length(field->buffers[0].string,
991 					   field->start_char,
992 					   field->row_xpos
993 					   + field->start_char) - 1;
994 
995 }
996 
997 /*
998  * Scroll the field backward the given number of characters.
999  */
1000 void
1001 _formi_hscroll_back(FIELD *field, unsigned int amt)
1002 {
1003 	field->start_char -= min(field->start_char, amt);
1004 	field->cursor_xpos =
1005 		_formi_tab_expanded_length(field->buffers[0].string,
1006 					   field->start_char,
1007 					   field->row_xpos
1008 					   + field->start_char) - 1;
1009 	if (field->cursor_xpos >= field->cols) {
1010 		field->row_xpos = 0;
1011 		field->cursor_xpos = 0;
1012 	}
1013 }
1014 
1015 /*
1016  * Find the different pages in the form fields and assign the form
1017  * page_starts array with the information to find them.
1018  */
1019 int
1020 _formi_find_pages(FORM *form)
1021 {
1022 	int i, cur_page = 0;
1023 
1024 	if ((form->page_starts = (_FORMI_PAGE_START *)
1025 	     malloc((form->max_page + 1) * sizeof(_FORMI_PAGE_START))) == NULL)
1026 		return E_SYSTEM_ERROR;
1027 
1028 	  /* initialise the page starts array */
1029 	memset(form->page_starts, 0,
1030 	       (form->max_page + 1) * sizeof(_FORMI_PAGE_START));
1031 
1032 	for (i =0; i < form->field_count; i++) {
1033 		if (form->fields[i]->page_break == 1)
1034 			cur_page++;
1035 		if (form->page_starts[cur_page].in_use == 0) {
1036 			form->page_starts[cur_page].in_use = 1;
1037 			form->page_starts[cur_page].first = i;
1038 			form->page_starts[cur_page].last = i;
1039 			form->page_starts[cur_page].top_left = i;
1040 			form->page_starts[cur_page].bottom_right = i;
1041 		} else {
1042 			form->page_starts[cur_page].last = i;
1043 			form->page_starts[cur_page].top_left =
1044 				_formi_top_left(form,
1045 						form->page_starts[cur_page].top_left,
1046 						i);
1047 			form->page_starts[cur_page].bottom_right =
1048 				_formi_bottom_right(form,
1049 						    form->page_starts[cur_page].bottom_right,
1050 						    i);
1051 		}
1052 	}
1053 
1054 	return E_OK;
1055 }
1056 
1057 /*
1058  * Completely redraw the field of the given form.
1059  */
1060 void
1061 _formi_redraw_field(FORM *form, int field)
1062 {
1063 	unsigned int pre, post, flen, slen, i, row, start;
1064 	unsigned int last_row, tab, cpos, len;
1065 	char *str, c;
1066 	FIELD *cur;
1067 #ifdef DEBUG
1068 	char buffer[100];
1069 #endif
1070 
1071 	cur = form->fields[field];
1072 	str = cur->buffers[0].string;
1073 	flen = cur->cols;
1074 	slen = 0;
1075 	start = 0;
1076 
1077 	if ((cur->row_count - cur->start_line) < cur->rows)
1078 		last_row = cur->row_count;
1079 	else
1080 		last_row = cur->start_line + cur->rows;
1081 
1082 	for (row = cur->start_line; row < last_row; row++) {
1083 		wmove(form->scrwin,
1084 		      (int) (cur->form_row + row - cur->start_line),
1085 		      (int) cur->form_col);
1086 		start = cur->lines[row].start;
1087 		if ((cur->rows + cur->nrows) == 1) {
1088 			if ((cur->start_char + cur->cols)
1089 			    >= cur->buffers[0].length)
1090 				len = cur->buffers[0].length;
1091 			else
1092 				len = cur->cols + cur->start_char;
1093 			slen = _formi_tab_expanded_length(
1094 				cur->buffers[0].string, cur->start_char, len);
1095 			if (slen > cur->cols)
1096 				slen = cur->cols;
1097 			slen += cur->start_char;
1098 		} else
1099 			slen = cur->lines[row].length;
1100 
1101 		if ((cur->opts & O_STATIC) == O_STATIC) {
1102 			switch (cur->justification) {
1103 			case JUSTIFY_RIGHT:
1104 				post = 0;
1105 				if (flen < slen)
1106 					pre = 0;
1107 				else
1108 					pre = flen - slen;
1109 				break;
1110 
1111 			case JUSTIFY_CENTER:
1112 				if (flen < slen) {
1113 					pre = 0;
1114 					post = 0;
1115 				} else {
1116 					pre = flen - slen;
1117 					post = pre = pre / 2;
1118 					  /* get padding right if
1119                                              centring is not even */
1120 					if ((post + pre + slen) < flen)
1121 						post++;
1122 				}
1123 				break;
1124 
1125 			case NO_JUSTIFICATION:
1126 			case JUSTIFY_LEFT:
1127 			default:
1128 				pre = 0;
1129 				if (flen <= slen)
1130 					post = 0;
1131 				else {
1132 					post = flen - slen;
1133 					if (post > flen)
1134 						post = flen;
1135 				}
1136 				break;
1137 			}
1138 		} else {
1139 			  /* dynamic fields are not justified */
1140 			pre = 0;
1141 			if (flen <= slen)
1142 				post = 0;
1143 			else {
1144 				post = flen - slen;
1145 				if (post > flen)
1146 					post = flen;
1147 			}
1148 
1149 			  /* but they do scroll.... */
1150 
1151 			if (pre > cur->start_char - start)
1152 				pre = pre - cur->start_char + start;
1153 			else
1154 				pre = 0;
1155 
1156 			if (slen > cur->start_char) {
1157 				slen -= cur->start_char;
1158 				if (slen > flen)
1159 					post = 0;
1160 				else
1161 					post = flen - slen;
1162 
1163 				if (post > flen)
1164 					post = flen;
1165 			} else {
1166 				slen = 0;
1167 				post = flen - pre;
1168 			}
1169 		}
1170 
1171 		if (form->cur_field == field)
1172 			wattrset(form->scrwin, cur->fore);
1173 		else
1174 			wattrset(form->scrwin, cur->back);
1175 
1176 #ifdef DEBUG
1177 		if (_formi_create_dbg_file() == E_OK) {
1178 			fprintf(dbg,
1179   "redraw_field: start=%d, pre=%d, slen=%d, flen=%d, post=%d, start_char=%d\n",
1180 				start, pre, slen, flen, post, cur->start_char);
1181 			if (str != NULL) {
1182 				strncpy(buffer,
1183 					&str[cur->start_char
1184 					    + cur->lines[row].start], flen);
1185 			} else {
1186 				strcpy(buffer, "(null)");
1187 			}
1188 			buffer[flen] = '\0';
1189 			fprintf(dbg, "redraw_field: %s\n", buffer);
1190 		}
1191 #endif
1192 
1193 		for (i = start + cur->start_char; i < pre; i++)
1194 			waddch(form->scrwin, cur->pad);
1195 
1196 #ifdef DEBUG
1197 		fprintf(dbg, "redraw_field: will add %d chars\n",
1198 			min(slen, flen));
1199 #endif
1200 		str = &cur->buffers[0].string[cur->start_char
1201 					     + cur->lines[row].start];
1202 
1203 		for (i = 0, cpos = cur->start_char; i < min(slen, flen);
1204 		     i++, str++, cpos++)
1205 		{
1206 			c = *str;
1207 			tab = 0; /* just to shut gcc up */
1208 #ifdef DEBUG
1209 			fprintf(dbg, "adding char str[%d]=%c\n",
1210 				cpos + cur->start_char + cur->lines[row].start,
1211 				c);
1212 #endif
1213 			if (((cur->opts & O_PUBLIC) != O_PUBLIC)) {
1214 				if (c == '\t')
1215 					tab = add_tab(form, cur, row,
1216 						      cpos, cur->pad);
1217 				else
1218 					waddch(form->scrwin, cur->pad);
1219 			} else if ((cur->opts & O_VISIBLE) == O_VISIBLE) {
1220 				if (c == '\t')
1221 					tab = add_tab(form, cur, row, cpos,
1222 						      ' ');
1223 				else
1224 					waddch(form->scrwin, c);
1225 			} else {
1226 				if (c == '\t')
1227 					tab = add_tab(form, cur, row, cpos,
1228 						      ' ');
1229 				else
1230 					waddch(form->scrwin, ' ');
1231 			}
1232 
1233 			  /*
1234 			   * If we have had a tab then skip forward
1235 			   * the requisite number of chars to keep
1236 			   * things in sync.
1237 			   */
1238 			if (c == '\t')
1239 				i += tab - 1;
1240 		}
1241 
1242 		for (i = 0; i < post; i++)
1243 			waddch(form->scrwin, cur->pad);
1244 	}
1245 
1246 	for (row = cur->row_count - cur->start_line; row < cur->rows; row++) {
1247 		wmove(form->scrwin, (int) (cur->form_row + row),
1248 		      (int) cur->form_col);
1249 		for (i = 0; i < cur->cols; i++) {
1250 			waddch(form->scrwin, cur->pad);
1251 		}
1252 	}
1253 
1254 	return;
1255 }
1256 
1257 /*
1258  * Add the correct number of the given character to simulate a tab
1259  * in the field.
1260  */
1261 static int
1262 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c)
1263 {
1264 	int j;
1265 	_formi_tab_t *ts = field->lines[row].tabs;
1266 
1267 	while ((ts != NULL) && (ts->pos != i))
1268 		ts = ts->fwd;
1269 
1270 #ifdef DEBUG
1271 	assert(ts != NULL);
1272 #endif
1273 
1274 	for (j = 0; j < ts->size; j++)
1275 		waddch(form->scrwin, c);
1276 
1277 	return ts->size;
1278 }
1279 
1280 
1281 /*
1282  * Display the fields attached to the form that are on the current page
1283  * on the screen.
1284  *
1285  */
1286 int
1287 _formi_draw_page(FORM *form)
1288 {
1289 	int i;
1290 
1291 	if (form->page_starts[form->page].in_use == 0)
1292 		return E_BAD_ARGUMENT;
1293 
1294 	wclear(form->scrwin);
1295 
1296 	for (i = form->page_starts[form->page].first;
1297 	     i <= form->page_starts[form->page].last; i++)
1298 		_formi_redraw_field(form, i);
1299 
1300 	return E_OK;
1301 }
1302 
1303 /*
1304  * Add the character c at the position pos in buffer 0 of the given field
1305  */
1306 int
1307 _formi_add_char(FIELD *field, unsigned int pos, char c)
1308 {
1309 	char *new, old_c;
1310 	unsigned int new_size;
1311 	int status;
1312 
1313 	  /*
1314 	   * If buffer has not had a string before, set it to a blank
1315 	   * string.  Everything should flow from there....
1316 	   */
1317 	if (field->buffers[0].string == NULL) {
1318 		set_field_buffer(field, 0, "");
1319 	}
1320 
1321 	if (_formi_validate_char(field, c) != E_OK) {
1322 #ifdef DEBUG
1323 		fprintf(dbg, "add_char: char %c failed char validation\n", c);
1324 #endif
1325 		return E_INVALID_FIELD;
1326 	}
1327 
1328 	if ((c == '\t') && (field->cols <= 8)) {
1329 #ifdef DEBUG
1330 		fprintf(dbg, "add_char: field too small for a tab\n");
1331 #endif
1332 		return E_NO_ROOM;
1333 	}
1334 
1335 #ifdef DEBUG
1336 	fprintf(dbg, "add_char: pos=%d, char=%c\n", pos, c);
1337 	fprintf(dbg, "add_char enter: xpos=%d, row_pos=%d, start=%d\n",
1338 		field->cursor_xpos, field->row_xpos, field->start_char);
1339 	fprintf(dbg, "add_char enter: length=%d(%d), allocated=%d\n",
1340 		field->buffers[0].length, strlen(field->buffers[0].string),
1341 		field->buffers[0].allocated);
1342 	fprintf(dbg, "add_char enter: %s\n", field->buffers[0].string);
1343 	fprintf(dbg, "add_char enter: buf0_status=%d\n", field->buf0_status);
1344 #endif
1345 	if (((field->opts & O_BLANK) == O_BLANK) &&
1346 	    (field->buf0_status == FALSE) &&
1347 	    ((field->row_xpos + field->start_char) == 0)) {
1348 		field->buffers[0].length = 0;
1349 		field->buffers[0].string[0] = '\0';
1350 		pos = 0;
1351 		field->start_char = 0;
1352 		field->start_line = 0;
1353 		field->row_count = 1;
1354 		field->row_xpos = 0;
1355 		field->cursor_xpos = 0;
1356 		field->cursor_ypos = 0;
1357 		field->lines[0].start = 0;
1358 		field->lines[0].end = 0;
1359 		field->lines[0].length = 0;
1360 	}
1361 
1362 
1363 	if ((field->overlay == 0)
1364 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1365 		  /* first check if the field can have more chars...*/
1366 		if (check_field_size(field) == FALSE)
1367 			return E_REQUEST_DENIED;
1368 
1369 		if (field->buffers[0].length + 1
1370 		    >= field->buffers[0].allocated) {
1371 			new_size = field->buffers[0].allocated + 64
1372 				- (field->buffers[0].allocated % 64);
1373 			if ((new = (char *) realloc(field->buffers[0].string,
1374 						    new_size )) == NULL)
1375 				return E_SYSTEM_ERROR;
1376 			field->buffers[0].allocated = new_size;
1377 			field->buffers[0].string = new;
1378 		}
1379 	}
1380 
1381 	if ((field->overlay == 0) && (field->buffers[0].length > pos)) {
1382 		bcopy(&field->buffers[0].string[pos],
1383 		      &field->buffers[0].string[pos + 1],
1384 		      field->buffers[0].length - pos + 1);
1385 	}
1386 
1387 	old_c = field->buffers[0].string[pos];
1388 	field->buffers[0].string[pos] = c;
1389 	if (pos >= field->buffers[0].length) {
1390 		  /* make sure the string is terminated if we are at the
1391 		   * end of the string, the terminator would be missing
1392 		   * if we are are at the end of the field.
1393 		   */
1394 		field->buffers[0].string[pos + 1] = '\0';
1395 	}
1396 
1397 	  /* only increment the length if we are inserting characters
1398 	   * OR if we are at the end of the field in overlay mode.
1399 	   */
1400 	if ((field->overlay == 0)
1401 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1402 		field->buffers[0].length++;
1403 		bump_lines(field, (int) pos, 1, TRUE);
1404 	} else if (field->overlay == 1)
1405 		bump_lines(field, (int) pos, 0, TRUE);
1406 
1407 	new_size = find_cur_line(field, pos);
1408 	_formi_calculate_tabs(field, new_size);
1409 
1410 	  /* wrap the field, if needed */
1411 	status = _formi_wrap_field(field, pos);
1412 
1413 	  /* just in case the row we are on wrapped */
1414 	new_size = find_cur_line(field, pos);
1415 
1416 	  /*
1417 	   * check the wrap worked or that we have not exceeded the
1418 	   * max field size - this can happen if the field is re-wrapped
1419 	   * and the row count is increased past the set limit.
1420 	   */
1421 	if ((status != E_OK) || (check_field_size(field) == FALSE)) {
1422 		if ((field->overlay == 0)
1423 		    || ((field->overlay == 1)
1424 			&& (pos >= field->buffers[0].length))) {
1425 			  /*
1426 			   * wrap failed for some reason, back out the
1427 			   * char insert
1428 			   */
1429 			bcopy(&field->buffers[0].string[pos + 1],
1430 			      &field->buffers[0].string[pos],
1431 			      field->buffers[0].length - pos);
1432 			field->buffers[0].length--;
1433 			bump_lines(field, (int) pos, -1, TRUE);
1434 			if (pos > 0)
1435 				pos--;
1436 		} else if (field->overlay == 1) {
1437 			  /* back out character overlay */
1438 			field->buffers[0].string[pos] = old_c;
1439 		}
1440 
1441 		new_size = find_cur_line(field, pos);
1442 		_formi_calculate_tabs(field, new_size);
1443 
1444 		_formi_wrap_field(field, pos);
1445 		  /*
1446 		   * If we are here then either the status is bad or we
1447 		   * simply ran out of room.  If the status is E_OK then
1448 		   * we ran out of room, let the form driver know this.
1449 		   */
1450 		if (status == E_OK)
1451 			status = E_REQUEST_DENIED;
1452 
1453 	} else {
1454 		field->buf0_status = TRUE;
1455 		if ((field->rows + field->nrows) == 1) {
1456 			if ((field->cursor_xpos < (field->cols - 1)) ||
1457 			    ((field->opts & O_STATIC) != O_STATIC)) {
1458 				field->row_xpos++;
1459 				field->cursor_xpos =
1460 					_formi_tab_expanded_length(
1461 						field->buffers[0].string,
1462 						field->start_char,
1463 						field->row_xpos
1464 						+ field->start_char);
1465 				if ((field->start_char + field->row_xpos)
1466 				    < field->buffers[0].length)
1467 					field->cursor_xpos--;
1468 			}
1469 
1470 			if (field->cursor_xpos > (field->cols - 1)) {
1471 				field->start_char =
1472 					tab_fit_window(field,
1473 						       field->start_char + field->row_xpos,
1474 						       field->cols);
1475 				field->row_xpos = pos - field->start_char + 1;
1476 				field->cursor_xpos =
1477 					_formi_tab_expanded_length(
1478 						field->buffers[0].string,
1479 						field->start_char,
1480 						field->row_xpos
1481 						+ field->start_char - 1);
1482 			}
1483 		} else {
1484 			if (new_size >= field->rows) {
1485 				field->cursor_ypos = field->rows - 1;
1486 				field->start_line = field->row_count
1487 					- field->cursor_ypos - 1;
1488 			} else
1489 				field->cursor_ypos = new_size;
1490 
1491 			if ((field->lines[new_size].start) <= (pos + 1)) {
1492 				field->row_xpos = pos
1493 					- field->lines[new_size].start + 1;
1494 				field->cursor_xpos =
1495 					_formi_tab_expanded_length(
1496 						&field->buffers[0].string[
1497 						    field->lines[new_size].start], 0,
1498 						field->row_xpos - 1);
1499 			} else {
1500 				field->row_xpos = 0;
1501 				field->cursor_xpos = 0;
1502 			}
1503 
1504 			  /*
1505 			   * Annoying corner case - if we are right in
1506 			   * the bottom right corner of the field we
1507 			   * need to scroll the field one line so the
1508 			   * cursor is positioned correctly in the
1509 			   * field.
1510 			   */
1511 			if ((field->cursor_xpos >= field->cols) &&
1512 			    (field->cursor_ypos == (field->rows - 1))) {
1513 				field->cursor_ypos--;
1514 				field->start_line++;
1515 			}
1516 		}
1517 	}
1518 
1519 #ifdef DEBUG
1520 	assert((field->cursor_xpos <= field->cols)
1521 	       && (field->cursor_ypos < 400000)
1522 	       && (field->start_line < 400000));
1523 
1524 	fprintf(dbg, "add_char exit: xpos=%d, row_pos=%d, start=%d\n",
1525 		field->cursor_xpos, field->row_xpos, field->start_char);
1526 	fprintf(dbg, "add_char_exit: length=%d(%d), allocated=%d\n",
1527 		field->buffers[0].length, strlen(field->buffers[0].string),
1528 		field->buffers[0].allocated);
1529 	fprintf(dbg, "add_char exit: ypos=%d, start_line=%d\n",
1530 		field->cursor_ypos, field->start_line);
1531 	fprintf(dbg,"add_char exit: %s\n", field->buffers[0].string);
1532 	fprintf(dbg, "add_char exit: buf0_status=%d\n", field->buf0_status);
1533 	fprintf(dbg, "add_char exit: status = %s\n",
1534 		(status == E_OK)? "OK" : "FAILED");
1535 #endif
1536 	return status;
1537 }
1538 
1539 /*
1540  * Manipulate the text in a field, this takes the given form and performs
1541  * the passed driver command on the current text field.  Returns 1 if the
1542  * text field was modified.
1543  */
1544 int
1545 _formi_manipulate_field(FORM *form, int c)
1546 {
1547 	FIELD *cur;
1548 	char *str, saved;
1549 	unsigned int i, start, end, pos, row, status, old_count, size;
1550 	unsigned int old_xpos, old_row_pos;
1551 	int len;
1552 
1553 	cur = form->fields[form->cur_field];
1554 
1555 #ifdef DEBUG
1556 	fprintf(dbg, "entry: request is REQ_%s\n", reqs[c - REQ_MIN_REQUEST]);
1557 	fprintf(dbg,
1558 	"entry: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
1559 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
1560 		cur->buffers[0].length,	cur->buffers[0].allocated);
1561 	fprintf(dbg, "entry: start_line=%d, ypos=%d\n", cur->start_line,
1562 		cur->cursor_ypos);
1563 	fprintf(dbg, "entry: string=");
1564 	if (cur->buffers[0].string == NULL)
1565 		fprintf(dbg, "(null)\n");
1566 	else
1567 		fprintf(dbg, "\"%s\"\n", cur->buffers[0].string);
1568 #endif
1569 
1570 	  /* Cannot manipulate a null string! */
1571 	if (cur->buffers[0].string == NULL)
1572 		return E_REQUEST_DENIED;
1573 
1574 	row = cur->start_line + cur->cursor_ypos;
1575 	saved = cur->buffers[0].string[cur->start_char + cur->row_xpos
1576 				      + cur->lines[row].start];
1577 
1578 	switch (c) {
1579 	case REQ_RIGHT_CHAR:
1580 		  /*
1581 		   * The right_char request performs the same function
1582 		   * as the next_char request except that the cursor is
1583 		   * not wrapped if it is at the end of the line, so
1584 		   * check if the cursor is at the end of the line and
1585 		   * deny the request otherwise just fall through to
1586 		   * the next_char request handler.
1587 		   */
1588 		if (cur->cursor_xpos >= cur->lines[row].length - 1)
1589 			return E_REQUEST_DENIED;
1590 
1591 		  /* FALLTHRU */
1592 
1593 	case REQ_NEXT_CHAR:
1594 		  /* for a dynamic field allow an offset of one more
1595 		   * char so we can insert chars after end of string.
1596 		   * Static fields cannot do this so deny request if
1597 		   * cursor is at the end of the field.
1598 		   */
1599 		if (((cur->opts & O_STATIC) == O_STATIC) &&
1600 		    (cur->row_xpos == cur->cols - 1) &&
1601 		    ((cur->rows + cur->nrows) == 1))
1602 			return E_REQUEST_DENIED;
1603 
1604 		if ((cur->row_xpos + cur->start_char + 1)
1605 		    > cur->buffers[0].length)
1606 			return E_REQUEST_DENIED;
1607 
1608 		if ((cur->rows + cur->nrows) == 1) {
1609 			if (saved == '\t')
1610 				cur->cursor_xpos += tab_size(cur, 0,
1611 							     cur->row_xpos
1612 							    + cur->start_char);
1613 			else
1614 				cur->cursor_xpos++;
1615 			cur->row_xpos++;
1616 			if (cur->cursor_xpos >= cur->cols - 1) {
1617 				pos = cur->row_xpos + cur->start_char;
1618 				cur->start_char =
1619 					tab_fit_window(cur,
1620 						       cur->start_char + cur->row_xpos,
1621 						       cur->cols);
1622 				cur->row_xpos = pos - cur->start_char;
1623 				cur->cursor_xpos =
1624 					_formi_tab_expanded_length(
1625 						cur->buffers[0].string,
1626 						cur->start_char,
1627 						cur->row_xpos
1628 						+ cur->start_char);
1629 				if ((cur->row_xpos + cur->start_char) <
1630 				    cur->buffers[0].length)
1631 					cur->cursor_xpos--;
1632 			}
1633 		} else {
1634 			if (cur->cursor_xpos >= (cur->lines[row].length - 1)) {
1635 				if ((row + 1) >= cur->row_count)
1636 					return E_REQUEST_DENIED;
1637 
1638 				cur->cursor_xpos = 0;
1639 				cur->row_xpos = 0;
1640 				if (cur->cursor_ypos == (cur->rows - 1))
1641 					cur->start_line++;
1642 				else
1643 					cur->cursor_ypos++;
1644 			} else {
1645 				old_xpos = cur->cursor_xpos;
1646 				old_row_pos = cur->row_xpos;
1647 				if (saved == '\t')
1648 					cur->cursor_xpos += tab_size(cur,
1649 							cur->lines[row].start,
1650 							cur->row_xpos);
1651 				else
1652 					cur->cursor_xpos++;
1653 				cur->row_xpos++;
1654 				if (cur->cursor_xpos
1655 				    >= cur->lines[row].length) {
1656 					if ((row + 1) >= cur->row_count) {
1657 						cur->cursor_xpos = old_xpos;
1658 						cur->row_xpos = old_row_pos;
1659 						return E_REQUEST_DENIED;
1660 					}
1661 
1662 					cur->cursor_xpos = 0;
1663 					cur->row_xpos = 0;
1664 					if (cur->cursor_ypos
1665 					    == (cur->rows - 1))
1666 						cur->start_line++;
1667 					else
1668 						cur->cursor_ypos++;
1669 				}
1670 			}
1671 		}
1672 
1673 		break;
1674 
1675 	case REQ_LEFT_CHAR:
1676 		  /*
1677 		   * The behaviour of left_char is the same as prev_char
1678 		   * except that the cursor will not wrap if it has
1679 		   * reached the LHS of the field, so just check this
1680 		   * and fall through if we are not at the LHS.
1681 		   */
1682 		if (cur->cursor_xpos == 0)
1683 			return E_REQUEST_DENIED;
1684 
1685 		  /* FALLTHRU */
1686 	case REQ_PREV_CHAR:
1687 		if ((cur->rows + cur->nrows) == 1) {
1688 			if (cur->row_xpos == 0) {
1689 				if (cur->start_char > 0)
1690 					cur->start_char--;
1691 				else
1692 					return E_REQUEST_DENIED;
1693 			} else {
1694 				cur->row_xpos--;
1695 				cur->cursor_xpos =
1696 					_formi_tab_expanded_length(
1697 						cur->buffers[0].string,
1698 						cur->start_char,
1699 						cur->row_xpos
1700 						+ cur->start_char) - 1;
1701 			}
1702 		} else {
1703 			if ((cur->cursor_xpos == 0) &&
1704 			    (cur->cursor_ypos == 0) &&
1705 			    (cur->start_line == 0))
1706 				return E_REQUEST_DENIED;
1707 
1708 			row = cur->start_line + cur->cursor_ypos;
1709 			pos = cur->lines[row].start + cur->row_xpos;
1710 			if ((pos >= cur->buffers[0].length) && (pos > 0))
1711 				pos--;
1712 
1713 			if (cur->cursor_xpos > 0) {
1714 				if (cur->buffers[0].string[pos] == '\t') {
1715 					size = tab_size(cur,
1716 							cur->lines[row].start,
1717 							pos
1718 							- cur->lines[row].start);
1719 					if (size > cur->cursor_xpos) {
1720 						cur->cursor_xpos = 0;
1721 						cur->row_xpos = 0;
1722 					} else {
1723 						cur->row_xpos--;
1724 						cur->cursor_xpos -= size;
1725 					}
1726 				} else {
1727 					cur->cursor_xpos--;
1728 					cur->row_xpos--;
1729 				}
1730 			} else {
1731 				if (cur->cursor_ypos > 0)
1732 					cur->cursor_ypos--;
1733 				else
1734 					cur->start_line--;
1735 				row = cur->start_line + cur->cursor_ypos;
1736 				cur->cursor_xpos = cur->lines[row].length - 1;
1737 				cur->row_xpos = cur->lines[row].end -
1738 					cur->lines[row].start;
1739 			}
1740 		}
1741 
1742 		break;
1743 
1744 	case REQ_DOWN_CHAR:
1745 		  /*
1746 		   * The down_char request has the same functionality as
1747 		   * the next_line request excepting that the field is not
1748 		   * scrolled if the cursor is at the bottom of the field.
1749 		   * Check to see if the cursor is at the bottom of the field
1750 		   * and if it is then deny the request otherwise fall
1751 		   * through to the next_line handler.
1752 		   */
1753 		if (cur->cursor_ypos >= cur->rows - 1)
1754 			return E_REQUEST_DENIED;
1755 
1756 		  /* FALLTHRU */
1757 
1758 	case REQ_NEXT_LINE:
1759 		if ((cur->start_line + cur->cursor_ypos + 1) >= cur->row_count)
1760 			return E_REQUEST_DENIED;
1761 
1762 		if ((cur->cursor_ypos + 1) >= cur->rows) {
1763 			cur->start_line++;
1764 		} else
1765 			cur->cursor_ypos++;
1766 		row = cur->cursor_ypos + cur->start_line;
1767 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos)
1768 			- cur->lines[row].start;
1769 		cur->cursor_xpos =
1770 			_formi_tab_expanded_length(
1771 				&cur->buffers[0].string[cur->lines[row].start],
1772 				0, cur->row_xpos);
1773 		break;
1774 
1775 	case REQ_UP_CHAR:
1776 		  /*
1777 		   * The up_char request has the same functionality as
1778 		   * the prev_line request excepting the field is not
1779 		   * scrolled, check if the cursor is at the top of the
1780 		   * field, if it is deny the request otherwise fall
1781 		   * through to the prev_line handler.
1782 		   */
1783 		if (cur->cursor_ypos == 0)
1784 			return E_REQUEST_DENIED;
1785 
1786 		  /* FALLTHRU */
1787 
1788 	case REQ_PREV_LINE:
1789 		if (cur->cursor_ypos == 0) {
1790 			if (cur->start_line == 0)
1791 				return E_REQUEST_DENIED;
1792 			cur->start_line--;
1793 		} else
1794 			cur->cursor_ypos--;
1795 		row = cur->cursor_ypos + cur->start_line;
1796 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos + 1)
1797 			- cur->lines[row].start;
1798 		cur->cursor_xpos =
1799 			_formi_tab_expanded_length(
1800 				&cur->buffers[0].string[cur->lines[row].start],
1801 				0, cur->row_xpos) - 1;
1802 		break;
1803 
1804 	case REQ_NEXT_WORD:
1805 		start = cur->lines[cur->start_line + cur->cursor_ypos].start
1806 			+ cur->row_xpos + cur->start_char;
1807 		str = cur->buffers[0].string;
1808 
1809 		start = find_eow(str, start);
1810 
1811 		  /* check if we hit the end */
1812 		if (str[start] == '\0')
1813 			return E_REQUEST_DENIED;
1814 
1815 		  /* otherwise we must have found the start of a word...*/
1816 		if ((cur->rows + cur->nrows) == 1) {
1817 			  /* single line field */
1818 			size = _formi_tab_expanded_length(str,
1819 				cur->start_char, start);
1820 			if (size < cur->cols) {
1821 				cur->row_xpos = start - cur->start_char;
1822 				cur->cursor_xpos = size - 1;
1823 			} else {
1824 				cur->start_char = start;
1825 				cur->row_xpos = 0;
1826 				cur->cursor_xpos = 0;
1827 			}
1828 		} else {
1829 			  /* multiline field */
1830 			row = find_cur_line(cur, start);
1831 			cur->row_xpos = start - cur->lines[row].start;
1832 			cur->cursor_xpos = _formi_tab_expanded_length(
1833 				&str[cur->lines[row].start],
1834 				0, cur->row_xpos) - 1;
1835 			if (row != (cur->start_line + cur->cursor_ypos)) {
1836 				if (cur->cursor_ypos == (cur->rows - 1)) {
1837 					cur->start_line = row - cur->rows + 1;
1838 				} else {
1839 					cur->cursor_ypos = row
1840 						- cur->start_line;
1841 				}
1842 			}
1843 		}
1844 		break;
1845 
1846 	case REQ_PREV_WORD:
1847 		start = cur->start_char + cur->row_xpos
1848 			+ cur->lines[cur->start_line + cur->cursor_ypos].start;
1849 		if (cur->start_char > 0)
1850 			start--;
1851 
1852 		if (start == 0)
1853 			return E_REQUEST_DENIED;
1854 
1855 		str = cur->buffers[0].string;
1856 
1857 		start = find_sow(str, start);
1858 
1859 		if ((cur->rows + cur->nrows) == 1) {
1860 			  /* single line field */
1861 			size = _formi_tab_expanded_length(str,
1862 				cur->start_char, start);
1863 
1864 			if (start > cur->start_char) {
1865 				cur->row_xpos = start - cur->start_char;
1866 				cur->cursor_xpos = size - 1;
1867 			} else {
1868 				cur->start_char = start;
1869 				cur->cursor_xpos = 0;
1870 				cur->row_xpos = 0;
1871 			}
1872 		} else {
1873 			  /* multiline field */
1874 			row = find_cur_line(cur, start);
1875 			cur->row_xpos = start - cur->lines[row].start;
1876 			cur->cursor_xpos = _formi_tab_expanded_length(
1877 				&str[cur->lines[row].start], 0,
1878 				cur->row_xpos) - 1;
1879 			if (row != (cur->start_line + cur->cursor_ypos)) {
1880 				if (cur->cursor_ypos == 0) {
1881 					cur->start_line = row;
1882 				} else {
1883 					if (cur->start_line > row) {
1884 						cur->start_line = row;
1885 						cur->cursor_ypos = 0;
1886 					} else {
1887 						cur->cursor_ypos = row -
1888 							cur->start_line;
1889 					}
1890 				}
1891 			}
1892 		}
1893 
1894 		break;
1895 
1896 	case REQ_BEG_FIELD:
1897 		cur->start_char = 0;
1898 		cur->start_line = 0;
1899 		cur->row_xpos = 0;
1900 		cur->cursor_xpos = 0;
1901 		cur->cursor_ypos = 0;
1902 		break;
1903 
1904 	case REQ_BEG_LINE:
1905 		cur->cursor_xpos = 0;
1906 		cur->row_xpos = 0;
1907 		cur->start_char = 0;
1908 		break;
1909 
1910 	case REQ_END_FIELD:
1911 		if (cur->row_count > cur->rows) {
1912 			cur->start_line = cur->row_count - cur->rows;
1913 			cur->cursor_ypos = cur->rows - 1;
1914 		} else {
1915 			cur->start_line = 0;
1916 			cur->cursor_ypos = cur->row_count - 1;
1917 		}
1918 
1919 		  /* we fall through here deliberately, we are on the
1920 		   * correct row, now we need to get to the end of the
1921 		   * line.
1922 		   */
1923 		  /* FALLTHRU */
1924 
1925 	case REQ_END_LINE:
1926 		row = cur->start_line + cur->cursor_ypos;
1927 		start = cur->lines[row].start;
1928 		end = cur->lines[row].end;
1929 
1930 		if ((cur->rows + cur->nrows) == 1) {
1931 			if (cur->lines[row].length > cur->cols - 1) {
1932 				if ((cur->opts & O_STATIC) != O_STATIC) {
1933 					cur->start_char = tab_fit_window(
1934 						cur, end, cur->cols) + 1;
1935 				} else {
1936 					cur->start_char = tab_fit_window(
1937 						cur, end, cur->cols);
1938 				}
1939 				cur->row_xpos = cur->buffers[0].length
1940 					- cur->start_char;
1941 				cur->cursor_xpos =
1942 					_formi_tab_expanded_length(
1943 					     cur->buffers[0].string,
1944 					     cur->start_char,
1945 					     cur->row_xpos + cur->start_char);
1946 			} else {
1947 				cur->row_xpos = end + 1;
1948 				cur->cursor_xpos = _formi_tab_expanded_length(
1949 					cur->buffers[0].string,
1950 					cur->start_char,
1951 					cur->row_xpos + cur->start_char);
1952 				if (((cur->opts & O_STATIC) == O_STATIC) &&
1953 				    ((cur->lines[row].length)
1954 				     == (cur->cols - 1)))
1955 					cur->cursor_xpos--;
1956 
1957 				cur->start_char = 0;
1958 			}
1959 		} else {
1960 			cur->row_xpos = end - start;
1961 			cur->cursor_xpos = cur->lines[row].length - 1;
1962 			if (row == (cur->row_count - 1)) {
1963 				cur->row_xpos++;
1964 				cur->cursor_xpos++;
1965 			}
1966 		}
1967 		break;
1968 
1969 	case REQ_NEW_LINE:
1970 		if ((status = split_line(cur,
1971 				cur->start_char + cur->row_xpos)) != E_OK)
1972 			return status;
1973 		break;
1974 
1975 	case REQ_INS_CHAR:
1976 		if ((status = _formi_add_char(cur, cur->start_char
1977 					      + cur->row_xpos,
1978 					      cur->pad)) != E_OK)
1979 			return status;
1980 		break;
1981 
1982 	case REQ_INS_LINE:
1983 		start = cur->lines[cur->start_line + cur->cursor_ypos].start;
1984 		if ((status = split_line(cur, start)) != E_OK)
1985 			return status;
1986 		break;
1987 
1988 	case REQ_DEL_CHAR:
1989 		if (cur->buffers[0].length == 0)
1990 			return E_REQUEST_DENIED;
1991 
1992 		row = cur->start_line + cur->cursor_ypos;
1993 		start = cur->start_char + cur->row_xpos
1994 			+ cur->lines[row].start;
1995 		end = cur->buffers[0].length;
1996 		if (start >= cur->buffers[0].length)
1997 			return E_REQUEST_DENIED;
1998 
1999 		if (start == cur->lines[row].end) {
2000 			if ((cur->rows + cur->nrows) > 1) {
2001 				/*
2002 				 * If we have more than one row, join the
2003 				 * next row to make things easier unless
2004 				 * we are at the end of the string, in
2005 				 * that case the join would fail but we
2006 				 * really want to delete the last char
2007 				 * in the field.
2008 				 */
2009 				if ((cur->row_count > 1)
2010 				    && (start != (end - 1))) {
2011 					if (_formi_join_line(cur,
2012 							     start,
2013 							     JOIN_NEXT_NW)
2014 					    != E_OK) {
2015 						return E_REQUEST_DENIED;
2016 					}
2017 				}
2018 			}
2019 		}
2020 
2021 		saved = cur->buffers[0].string[start];
2022 		bcopy(&cur->buffers[0].string[start + 1],
2023 		      &cur->buffers[0].string[start],
2024 		      (unsigned) end - start + 1);
2025 		bump_lines(cur, _FORMI_USE_CURRENT, -1, TRUE);
2026 		cur->buffers[0].length--;
2027 
2028 		  /*
2029 		   * recalculate tabs for a single line field, multiline
2030 		   * fields will do this when the field is wrapped.
2031 		   */
2032 		if ((cur->rows + cur->nrows) == 1)
2033 			_formi_calculate_tabs(cur, 0);
2034 		  /*
2035 		   * if we are at the end of the string then back the
2036 		   * cursor pos up one to stick on the end of the line
2037 		   */
2038 		if (start == cur->buffers[0].length) {
2039 			if (cur->buffers[0].length > 1) {
2040 				if ((cur->rows + cur->nrows) == 1) {
2041 					pos = cur->row_xpos + cur->start_char;
2042 					cur->start_char =
2043 						tab_fit_window(cur,
2044 							       cur->start_char + cur->row_xpos,
2045 							       cur->cols);
2046 					cur->row_xpos = pos - cur->start_char
2047 						- 1;
2048 					cur->cursor_xpos =
2049 						_formi_tab_expanded_length(
2050 							cur->buffers[0].string,
2051 							cur->start_char,
2052 							cur->row_xpos
2053 							+ cur->start_char);
2054 				} else {
2055 					if (cur->row_xpos == 0) {
2056 						if (cur->lines[row].start !=
2057 						    cur->buffers[0].length) {
2058 							if (_formi_join_line(
2059 								cur,
2060 								cur->lines[row].start,
2061 								JOIN_PREV_NW)
2062 							    != E_OK) {
2063 								return E_REQUEST_DENIED;
2064 							}
2065 						} else {
2066 							if (cur->row_count > 1)
2067 								cur->row_count--;
2068 						}
2069 
2070 						row = cur->start_line
2071 							+ cur->cursor_ypos;
2072 						if (row > 0)
2073 							row--;
2074 					}
2075 
2076 					cur->row_xpos = start
2077 						- cur->lines[row].start - 1;
2078 					cur->cursor_xpos =
2079 						_formi_tab_expanded_length(
2080 							&cur->buffers[0].string[cur->lines[row].start],
2081 							0, cur->row_xpos);
2082 					if ((cur->cursor_xpos > 0)
2083 					    && (start != (cur->buffers[0].length - 1)))
2084 						cur->cursor_xpos--;
2085 					if (row >= cur->rows)
2086 						cur->start_line = row
2087 							- cur->cursor_ypos;
2088 					else {
2089 						cur->start_line = 0;
2090 						cur->cursor_ypos = row;
2091 					}
2092 				}
2093 
2094 				start--;
2095 			} else {
2096 				start = 0;
2097 				cur->row_xpos = 0;
2098 				cur->cursor_xpos = 0;
2099 			}
2100 		}
2101 
2102 		if ((cur->rows + cur->nrows) > 1) {
2103 			if (_formi_wrap_field(cur, start) != E_OK) {
2104 				bcopy(&cur->buffers[0].string[start],
2105 				      &cur->buffers[0].string[start + 1],
2106 				      (unsigned) end - start);
2107 				cur->buffers[0].length++;
2108 				cur->buffers[0].string[start] = saved;
2109 				bump_lines(cur, _FORMI_USE_CURRENT, 1, TRUE);
2110 				_formi_wrap_field(cur, start);
2111 				return E_REQUEST_DENIED;
2112 			}
2113 		}
2114 		break;
2115 
2116 	case REQ_DEL_PREV:
2117 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0)
2118 		    && (cur->start_line == 0) && (cur->cursor_ypos == 0))
2119 			   return E_REQUEST_DENIED;
2120 
2121 		row = cur->start_line + cur->cursor_ypos;
2122 		start = cur->row_xpos + cur->start_char
2123 			+ cur->lines[row].start;
2124 		end = cur->buffers[0].length;
2125 
2126 		if ((cur->start_char + cur->row_xpos) == 0) {
2127 			  /*
2128 			   * Join this line to the next one, but only if
2129 			   * we are not at the end of the string because
2130 			   * in that case there are no characters to join.
2131 			   */
2132 			if (cur->lines[row].start != end) {
2133 				if (_formi_join_line(cur,
2134 						     cur->lines[row].start,
2135 						     JOIN_PREV_NW) != E_OK) {
2136 					return E_REQUEST_DENIED;
2137 				}
2138 			} else {
2139 				/* but we do want the row count decremented */
2140 				if (cur->row_count > 1)
2141 					cur->row_count--;
2142 			}
2143 		}
2144 
2145 		saved = cur->buffers[0].string[start - 1];
2146 		bcopy(&cur->buffers[0].string[start],
2147 		      &cur->buffers[0].string[start - 1],
2148 		      (unsigned) end - start + 1);
2149 		bump_lines(cur, (int) start - 1, -1, TRUE);
2150 		cur->buffers[0].length--;
2151 
2152 		if ((cur->rows + cur->nrows) == 1) {
2153 			_formi_calculate_tabs(cur, 0);
2154 			pos = cur->row_xpos + cur->start_char;
2155 			if (pos > 0)
2156 				pos--;
2157 			cur->start_char =
2158 				tab_fit_window(cur,
2159 					       cur->start_char + cur->row_xpos,
2160 					       cur->cols);
2161 			cur->row_xpos = pos - cur->start_char;
2162 			cur->cursor_xpos =
2163 				_formi_tab_expanded_length(
2164 					cur->buffers[0].string,
2165 					cur->start_char,
2166 					cur->row_xpos
2167 					+ cur->start_char);
2168 		} else {
2169 			pos = start - 1;
2170 			if (pos >= cur->buffers[0].length)
2171 				pos = cur->buffers[0].length - 1;
2172 
2173 			if ((_formi_wrap_field(cur, pos) != E_OK)) {
2174 				bcopy(&cur->buffers[0].string[start - 1],
2175 				      &cur->buffers[0].string[start],
2176 				      (unsigned) end - start);
2177 				cur->buffers[0].length++;
2178 				cur->buffers[0].string[start - 1] = saved;
2179 				bump_lines(cur, (int) start - 1, 1, TRUE);
2180 				_formi_wrap_field(cur, pos);
2181 				return E_REQUEST_DENIED;
2182 			}
2183 
2184 			row = find_cur_line(cur, pos);
2185 			cur->row_xpos = start - cur->lines[row].start - 1;
2186 			cur->cursor_xpos = _formi_tab_expanded_length(
2187 				&cur->buffers[0].string[cur->lines[row].start],
2188 				0, cur->row_xpos);
2189 			if ((cur->cursor_xpos > 0)
2190 			    && (pos != (cur->buffers[0].length - 1)))
2191 				cur->cursor_xpos--;
2192 
2193 			if (row >= cur->rows)
2194 				cur->start_line = row - cur->cursor_ypos;
2195 			else {
2196 				cur->start_line = 0;
2197 				cur->cursor_ypos = row;
2198 			}
2199 		}
2200 		break;
2201 
2202 	case REQ_DEL_LINE:
2203 		row = cur->start_line + cur->cursor_ypos;
2204 		start = cur->lines[row].start;
2205 		end = cur->lines[row].end;
2206 		bcopy(&cur->buffers[0].string[end + 1],
2207 		      &cur->buffers[0].string[start],
2208 		      (unsigned) cur->buffers[0].length - end + 1);
2209 
2210 		if (((cur->rows + cur->nrows) == 1) ||
2211 		    (cur->row_count == 1)) {
2212 			  /* single line case */
2213 			cur->buffers[0].length = 0;
2214 			cur->lines[0].end = cur->lines[0].length = 0;
2215 			cur->cursor_xpos = cur->row_xpos = 0;
2216 			cur->cursor_ypos = 0;
2217 		} else {
2218 			  /* multiline field */
2219 			old_count = cur->row_count;
2220 			cur->row_count--;
2221 			if (cur->row_count == 0)
2222 				cur->row_count = 1;
2223 
2224 			if (cur->row_count > 1)
2225 				bcopy(&cur->lines[row + 1],
2226 				      &cur->lines[row],
2227 				      (unsigned) (cur->row_count - row)
2228 				      * sizeof(struct _formi_field_lines));
2229 
2230 			cur->lines[row].start = start;
2231 			len = start - end - 1; /* yes, this is negative */
2232 
2233 			if (row < (cur->row_count - 1))
2234 				bump_lines(cur, (int) start, len, FALSE);
2235 			else if (old_count == 1) {
2236 				cur->lines[0].end = cur->lines[0].length = 0;
2237 				cur->cursor_xpos = 0;
2238 				cur->row_xpos = 0;
2239 				cur->cursor_ypos = 0;
2240 			} else if (cur->row_count == 1) {
2241 				cur->lines[0].length = cur->buffers[0].length
2242 					+ len;
2243 				cur->lines[0].end = cur->lines[0].length - 1;
2244 			}
2245 
2246 			cur->buffers[0].length += len;
2247 
2248 			if (row > (cur->row_count - 1)) {
2249 				row--;
2250 				if (cur->cursor_ypos == 0) {
2251 					if (cur->start_line > 0) {
2252 						cur->start_line--;
2253 					}
2254 				} else {
2255 					cur->cursor_ypos--;
2256 				}
2257 			}
2258 
2259 			if (old_count > 1) {
2260 				if (cur->cursor_xpos > cur->lines[row].length) {
2261 					cur->cursor_xpos =
2262 						cur->lines[row].length - 1;
2263 					cur->row_xpos = cur->lines[row].end;
2264 				}
2265 
2266 				if (row >= cur->rows)
2267 					cur->start_line = row
2268 						- cur->cursor_ypos;
2269 				else {
2270 					cur->start_line = 0;
2271 					cur->cursor_ypos = row;
2272 				}
2273 			}
2274 		}
2275 		break;
2276 
2277 	case REQ_DEL_WORD:
2278 		start = cur->start_char + cur->row_xpos
2279 			+ cur->lines[row].start;
2280 		str = cur->buffers[0].string;
2281 
2282 		end = find_eow(str, start);
2283 
2284 		  /*
2285 		   * If not at the start of a word then find the start,
2286 		   * we cannot blindly call find_sow because this will
2287 		   * skip back a word if we are already at the start of
2288 		   * a word.
2289 		   */
2290 		if ((start > 0)
2291 		    && !(isblank(str[start - 1]) && !isblank(str[start])))
2292 			start = find_sow(cur->buffers[0].string, start);
2293 		bcopy(&cur->buffers[0].string[end],
2294 		      &cur->buffers[0].string[start],
2295 		      (unsigned) cur->buffers[0].length - end + 1);
2296 		len = end - start;
2297 		cur->buffers[0].length -= len;
2298 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2299 
2300 		if ((cur->rows + cur->nrows) > 1) {
2301 			row = cur->start_line + cur->cursor_ypos;
2302 			if ((row + 1) < cur->row_count) {
2303 				/*
2304 				 * if not on the last row we need to
2305 				 * join on the next row so the line
2306 				 * will be re-wrapped.
2307 				 */
2308 				_formi_join_line(cur, cur->lines[row].end,
2309 						 JOIN_NEXT_NW);
2310 			}
2311 			_formi_wrap_field(cur, start);
2312 			row = find_cur_line(cur, start);
2313 			cur->row_xpos = start - cur->lines[row].start;
2314 			cur->cursor_xpos = _formi_tab_expanded_length(
2315 				&cur->buffers[0].string[cur->lines[row].start],
2316 				0, cur->row_xpos);
2317 			if ((cur->cursor_xpos > 0)
2318 			    && (start != (cur->buffers[0].length - 1)))
2319 				cur->cursor_xpos--;
2320 		} else {
2321 			_formi_calculate_tabs(cur, 0);
2322 			cur->row_xpos = start - cur->start_char;
2323 			if (cur->row_xpos > 0)
2324 				cur->row_xpos--;
2325 			cur->cursor_xpos = _formi_tab_expanded_length(
2326 				cur->buffers[0].string, cur->start_char,
2327 				cur->row_xpos);
2328 			if (cur->cursor_xpos > 0)
2329 				cur->cursor_xpos--;
2330 		}
2331 		break;
2332 
2333 	case REQ_CLR_EOL:
2334 		row = cur->start_line + cur->cursor_ypos;
2335 		start = cur->start_char + cur->cursor_xpos;
2336 		end = cur->lines[row].end;
2337 		len = end - start;
2338 		bcopy(&cur->buffers[0].string[end + 1],
2339 		      &cur->buffers[0].string[start],
2340 		      cur->buffers[0].length - end + 1);
2341 		cur->buffers[0].length -= len;
2342 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2343 
2344 		if (cur->cursor_xpos > cur->lines[row].length) {
2345 			cur->row_xpos = cur->lines[row].end;
2346 			cur->cursor_xpos = cur->lines[row].length;
2347 		}
2348 		break;
2349 
2350 	case REQ_CLR_EOF:
2351 		row = cur->start_line + cur->cursor_ypos;
2352 		cur->buffers[0].string[cur->start_char
2353 				      + cur->cursor_xpos] = '\0';
2354 		cur->buffers[0].length = strlen(cur->buffers[0].string);
2355 		cur->lines[row].end = cur->buffers[0].length;
2356 		cur->lines[row].length = cur->lines[row].end
2357 			- cur->lines[row].start;
2358 
2359 		for (i = cur->start_char + cur->row_xpos;
2360 		     i < cur->buffers[0].length; i++)
2361 			cur->buffers[0].string[i] = cur->pad;
2362 		break;
2363 
2364 	case REQ_CLR_FIELD:
2365 		cur->buffers[0].string[0] = '\0';
2366 		cur->buffers[0].length = 0;
2367 		cur->row_count = 1;
2368 		cur->start_line = 0;
2369 		cur->cursor_ypos = 0;
2370 		cur->cursor_xpos = 0;
2371 		cur->row_xpos = 0;
2372 		cur->start_char = 0;
2373 		cur->lines[0].start = 0;
2374 		cur->lines[0].end = 0;
2375 		cur->lines[0].length = 0;
2376 		break;
2377 
2378 	case REQ_OVL_MODE:
2379 		cur->overlay = 1;
2380 		break;
2381 
2382 	case REQ_INS_MODE:
2383 		cur->overlay = 0;
2384 		break;
2385 
2386 	case REQ_SCR_FLINE:
2387 		_formi_scroll_fwd(cur, 1);
2388 		break;
2389 
2390 	case REQ_SCR_BLINE:
2391 		_formi_scroll_back(cur, 1);
2392 		break;
2393 
2394 	case REQ_SCR_FPAGE:
2395 		_formi_scroll_fwd(cur, cur->rows);
2396 		break;
2397 
2398 	case REQ_SCR_BPAGE:
2399 		_formi_scroll_back(cur, cur->rows);
2400 		break;
2401 
2402 	case REQ_SCR_FHPAGE:
2403 		_formi_scroll_fwd(cur, cur->rows / 2);
2404 		break;
2405 
2406 	case REQ_SCR_BHPAGE:
2407 		_formi_scroll_back(cur, cur->rows / 2);
2408 		break;
2409 
2410 	case REQ_SCR_FCHAR:
2411 		_formi_hscroll_fwd(cur, 1);
2412 		break;
2413 
2414 	case REQ_SCR_BCHAR:
2415 		_formi_hscroll_back(cur, 1);
2416 		break;
2417 
2418 	case REQ_SCR_HFLINE:
2419 		_formi_hscroll_fwd(cur, cur->cols);
2420 		break;
2421 
2422 	case REQ_SCR_HBLINE:
2423 		_formi_hscroll_back(cur, cur->cols);
2424 		break;
2425 
2426 	case REQ_SCR_HFHALF:
2427 		_formi_hscroll_fwd(cur, cur->cols / 2);
2428 		break;
2429 
2430 	case REQ_SCR_HBHALF:
2431 		_formi_hscroll_back(cur, cur->cols / 2);
2432 		break;
2433 
2434 	default:
2435 		return 0;
2436 	}
2437 
2438 #ifdef DEBUG
2439 	fprintf(dbg,
2440 	 "exit: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
2441 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
2442 		cur->buffers[0].length,	cur->buffers[0].allocated);
2443 	fprintf(dbg, "exit: start_line=%d, ypos=%d\n", cur->start_line,
2444 		cur->cursor_ypos);
2445 	fprintf(dbg, "exit: string=\"%s\"\n", cur->buffers[0].string);
2446 	assert ((cur->cursor_xpos < INT_MAX) && (cur->row_xpos < INT_MAX)
2447 		&& (cur->cursor_xpos >= cur->row_xpos));
2448 #endif
2449 	return 1;
2450 }
2451 
2452 /*
2453  * Validate the give character by passing it to any type character
2454  * checking routines, if they exist.
2455  */
2456 int
2457 _formi_validate_char(FIELD *field, char c)
2458 {
2459 	int ret_val;
2460 
2461 	if (field->type == NULL)
2462 		return E_OK;
2463 
2464 	ret_val = E_INVALID_FIELD;
2465 	_formi_do_char_validation(field, field->type, c, &ret_val);
2466 
2467 	return ret_val;
2468 }
2469 
2470 
2471 /*
2472  * Perform the validation of the character, invoke all field_type validation
2473  * routines.  If the field is ok then update ret_val to E_OK otherwise
2474  * ret_val is not changed.
2475  */
2476 static void
2477 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val)
2478 {
2479 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2480 		_formi_do_char_validation(field, type->link->next, c, ret_val);
2481 		_formi_do_char_validation(field, type->link->prev, c, ret_val);
2482 	} else {
2483 		if (type->char_check == NULL)
2484 			*ret_val = E_OK;
2485 		else {
2486 			if (type->char_check((int)(unsigned char) c,
2487 					     field->args) == TRUE)
2488 				*ret_val = E_OK;
2489 		}
2490 	}
2491 }
2492 
2493 /*
2494  * Validate the current field.  If the field validation returns success then
2495  * return E_OK otherwise return E_INVALID_FIELD.
2496  *
2497  */
2498 int
2499 _formi_validate_field(FORM *form)
2500 {
2501 	FIELD *cur;
2502 	char *bp;
2503 	int ret_val, count;
2504 
2505 
2506 	if ((form == NULL) || (form->fields == NULL) ||
2507 	    (form->fields[0] == NULL))
2508 		return E_INVALID_FIELD;
2509 
2510 	cur = form->fields[form->cur_field];
2511 
2512 	bp = cur->buffers[0].string;
2513 	count = _formi_skip_blanks(bp, 0);
2514 
2515 	  /* check if we have a null field, depending on the nullok flag
2516 	   * this may be acceptable or not....
2517 	   */
2518 	if (cur->buffers[0].string[count] == '\0') {
2519 		if ((cur->opts & O_NULLOK) == O_NULLOK)
2520 			return E_OK;
2521 		else
2522 			return E_INVALID_FIELD;
2523 	}
2524 
2525 	  /* check if an unmodified field is ok */
2526 	if (cur->buf0_status == 0) {
2527 		if ((cur->opts & O_PASSOK) == O_PASSOK)
2528 			return E_OK;
2529 		else
2530 			return E_INVALID_FIELD;
2531 	}
2532 
2533 	  /* if there is no type then just accept the field */
2534 	if (cur->type == NULL)
2535 		return E_OK;
2536 
2537 	ret_val = E_INVALID_FIELD;
2538 	_formi_do_validation(cur, cur->type, &ret_val);
2539 
2540 	return ret_val;
2541 }
2542 
2543 /*
2544  * Perform the validation of the field, invoke all field_type validation
2545  * routines.  If the field is ok then update ret_val to E_OK otherwise
2546  * ret_val is not changed.
2547  */
2548 static void
2549 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val)
2550 {
2551 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2552 		_formi_do_validation(field, type->link->next, ret_val);
2553 		_formi_do_validation(field, type->link->prev, ret_val);
2554 	} else {
2555 		if (type->field_check == NULL)
2556 			*ret_val = E_OK;
2557 		else {
2558 			if (type->field_check(field, field_buffer(field, 0))
2559 			    == TRUE)
2560 				*ret_val = E_OK;
2561 		}
2562 	}
2563 }
2564 
2565 /*
2566  * Select the next/previous choice for the field, the driver command
2567  * selecting the direction will be passed in c.  Return 1 if a choice
2568  * selection succeeded, 0 otherwise.
2569  */
2570 int
2571 _formi_field_choice(FORM *form, int c)
2572 {
2573 	FIELDTYPE *type;
2574 	FIELD *field;
2575 
2576 	if ((form == NULL) || (form->fields == NULL) ||
2577 	    (form->fields[0] == NULL) ||
2578 	    (form->fields[form->cur_field]->type == NULL))
2579 		return 0;
2580 
2581 	field = form->fields[form->cur_field];
2582 	type = field->type;
2583 
2584 	switch (c) {
2585 	case REQ_NEXT_CHOICE:
2586 		if (type->next_choice == NULL)
2587 			return 0;
2588 		else
2589 			return type->next_choice(field,
2590 						 field_buffer(field, 0));
2591 
2592 	case REQ_PREV_CHOICE:
2593 		if (type->prev_choice == NULL)
2594 			return 0;
2595 		else
2596 			return type->prev_choice(field,
2597 						 field_buffer(field, 0));
2598 
2599 	default: /* should never happen! */
2600 		return 0;
2601 	}
2602 }
2603 
2604 /*
2605  * Update the fields if they have changed.  The parameter old has the
2606  * previous current field as the current field may have been updated by
2607  * the driver.  Return 1 if the form page needs updating.
2608  *
2609  */
2610 int
2611 _formi_update_field(FORM *form, int old_field)
2612 {
2613 	int cur, i;
2614 
2615 	cur = form->cur_field;
2616 
2617 	if (old_field != cur) {
2618 		if (!((cur >= form->page_starts[form->page].first) &&
2619 		      (cur <= form->page_starts[form->page].last))) {
2620 			  /* not on same page any more */
2621 			for (i = 0; i < form->max_page; i++) {
2622 				if ((form->page_starts[i].in_use == 1) &&
2623 				    (form->page_starts[i].first <= cur) &&
2624 				    (form->page_starts[i].last >= cur)) {
2625 					form->page = i;
2626 					return 1;
2627 				}
2628 			}
2629 		}
2630 	}
2631 
2632 	_formi_redraw_field(form, old_field);
2633 	_formi_redraw_field(form, form->cur_field);
2634 	return 0;
2635 }
2636 
2637 /*
2638  * Compare function for the field sorting
2639  *
2640  */
2641 static int
2642 field_sort_compare(const void *one, const void *two)
2643 {
2644 	const FIELD *a, *b;
2645 	int tl;
2646 
2647 	  /* LINTED const castaway; we don't modify these! */
2648 	a = (const FIELD *) *((const FIELD **) one);
2649 	b = (const FIELD *) *((const FIELD **) two);
2650 
2651 	if (a == NULL)
2652 		return 1;
2653 
2654 	if (b == NULL)
2655 		return -1;
2656 
2657 	  /*
2658 	   * First check the page, we want the fields sorted by page.
2659 	   *
2660 	   */
2661 	if (a->page != b->page)
2662 		return ((a->page > b->page)? 1 : -1);
2663 
2664 	tl = _formi_top_left(a->parent, a->index, b->index);
2665 
2666 	  /*
2667 	   * sort fields left to right, top to bottom so the top left is
2668 	   * the less than value....
2669 	   */
2670 	return ((tl == a->index)? -1 : 1);
2671 }
2672 
2673 /*
2674  * Sort the fields in a form ready for driver traversal.
2675  */
2676 void
2677 _formi_sort_fields(FORM *form)
2678 {
2679 	FIELD **sort_area;
2680 	int i;
2681 
2682 	CIRCLEQ_INIT(&form->sorted_fields);
2683 
2684 	if ((sort_area = (FIELD **) malloc(sizeof(FIELD *) * form->field_count))
2685 	    == NULL)
2686 		return;
2687 
2688 	bcopy(form->fields, sort_area, sizeof(FIELD *) * form->field_count);
2689 	qsort(sort_area, (unsigned) form->field_count, sizeof(FIELD *),
2690 	      field_sort_compare);
2691 
2692 	for (i = 0; i < form->field_count; i++)
2693 		CIRCLEQ_INSERT_TAIL(&form->sorted_fields, sort_area[i], glue);
2694 
2695 	free(sort_area);
2696 }
2697 
2698 /*
2699  * Set the neighbours for all the fields in the given form.
2700  */
2701 void
2702 _formi_stitch_fields(FORM *form)
2703 {
2704 	int above_row, below_row, end_above, end_below, cur_row, real_end;
2705 	FIELD *cur, *above, *below;
2706 
2707 	  /*
2708 	   * check if the sorted fields circle queue is empty, just
2709 	   * return if it is.
2710 	   */
2711 	if (CIRCLEQ_EMPTY(&form->sorted_fields))
2712 		return;
2713 
2714 	  /* initially nothing is above..... */
2715 	above_row = -1;
2716 	end_above = TRUE;
2717 	above = NULL;
2718 
2719 	  /* set up the first field as the current... */
2720 	cur = CIRCLEQ_FIRST(&form->sorted_fields);
2721 	cur_row = cur->form_row;
2722 
2723 	  /* find the first field on the next row if any */
2724 	below = CIRCLEQ_NEXT(cur, glue);
2725 	below_row = -1;
2726 	end_below = TRUE;
2727 	real_end = TRUE;
2728 	while (below != (void *)&form->sorted_fields) {
2729 		if (below->form_row != cur_row) {
2730 			below_row = below->form_row;
2731 			end_below = FALSE;
2732 			real_end = FALSE;
2733 			break;
2734 		}
2735 		below = CIRCLEQ_NEXT(below, glue);
2736 	}
2737 
2738 	  /* walk the sorted fields, setting the neighbour pointers */
2739 	while (cur != (void *) &form->sorted_fields) {
2740 		if (cur == CIRCLEQ_FIRST(&form->sorted_fields))
2741 			cur->left = NULL;
2742 		else
2743 			cur->left = CIRCLEQ_PREV(cur, glue);
2744 
2745 		if (cur == CIRCLEQ_LAST(&form->sorted_fields))
2746 			cur->right = NULL;
2747 		else
2748 			cur->right = CIRCLEQ_NEXT(cur, glue);
2749 
2750 		if (end_above == TRUE)
2751 			cur->up = NULL;
2752 		else {
2753 			cur->up = above;
2754 			above = CIRCLEQ_NEXT(above, glue);
2755 			if (above_row != above->form_row) {
2756 				end_above = TRUE;
2757 				above_row = above->form_row;
2758 			}
2759 		}
2760 
2761 		if (end_below == TRUE)
2762 			cur->down = NULL;
2763 		else {
2764 			cur->down = below;
2765 			below = CIRCLEQ_NEXT(below, glue);
2766 			if (below == (void *) &form->sorted_fields) {
2767 				end_below = TRUE;
2768 				real_end = TRUE;
2769 			} else if (below_row != below->form_row) {
2770 				end_below = TRUE;
2771 				below_row = below->form_row;
2772 			}
2773 		}
2774 
2775 		cur = CIRCLEQ_NEXT(cur, glue);
2776 		if ((cur != (void *) &form->sorted_fields)
2777 		    && (cur_row != cur->form_row)) {
2778 			cur_row = cur->form_row;
2779 			if (end_above == FALSE) {
2780 				for (; above != CIRCLEQ_FIRST(&form->sorted_fields);
2781 				     above = CIRCLEQ_NEXT(above, glue)) {
2782 					if (above->form_row != above_row) {
2783 						above_row = above->form_row;
2784 						break;
2785 					}
2786 				}
2787 			} else if (above == NULL) {
2788 				above = CIRCLEQ_FIRST(&form->sorted_fields);
2789 				end_above = FALSE;
2790 				above_row = above->form_row;
2791 			} else
2792 				end_above = FALSE;
2793 
2794 			if (end_below == FALSE) {
2795 				while (below_row == below->form_row) {
2796 					below = CIRCLEQ_NEXT(below,
2797 							     glue);
2798 					if (below ==
2799 					    (void *)&form->sorted_fields) {
2800 						real_end = TRUE;
2801 						end_below = TRUE;
2802 						break;
2803 					}
2804 				}
2805 
2806 				if (below != (void *)&form->sorted_fields)
2807 					below_row = below->form_row;
2808 			} else if (real_end == FALSE)
2809 				end_below = FALSE;
2810 
2811 		}
2812 	}
2813 }
2814 
2815 /*
2816  * Calculate the length of the displayed line allowing for any tab
2817  * characters that need to be expanded.  We assume that the tab stops
2818  * are 8 characters apart.  The parameters start and end are the
2819  * character positions in the string str we want to get the length of,
2820  * the function returns the number of characters from the start
2821  * position to the end position that should be displayed after any
2822  * intervening tabs have been expanded.
2823  */
2824 int
2825 _formi_tab_expanded_length(char *str, unsigned int start, unsigned int end)
2826 {
2827 	int len, start_len, i;
2828 
2829 	  /* if we have a null string then there is no length */
2830 	if (str[0] == '\0')
2831 		return 0;
2832 
2833 	len = 0;
2834 	start_len = 0;
2835 
2836 	  /*
2837 	   * preceding tabs affect the length tabs in the span, so
2838 	   * we need to calculate the length including the stuff before
2839 	   * start and then subtract off the unwanted bit.
2840 	   */
2841 	for (i = 0; i <= end; i++) {
2842 		if (i == start) /* stash preamble length for later */
2843 			start_len = len;
2844 
2845 		if (str[i] == '\0')
2846 			break;
2847 
2848 		if (str[i] == '\t')
2849 			len = len - (len % 8) + 8;
2850 		else
2851 			len++;
2852 	}
2853 
2854 #ifdef DEBUG
2855 	if (dbg != NULL) {
2856 		fprintf(dbg,
2857 		    "tab_expanded: start=%d, end=%d, expanded=%d (diff=%d)\n",
2858 			start, end, (len - start_len), (end - start));
2859 	}
2860 #endif
2861 
2862 	return (len - start_len);
2863 }
2864 
2865 /*
2866  * Calculate the tab stops on a given line in the field and set up
2867  * the tabs list with the results.  We do this by scanning the line for tab
2868  * characters and if one is found, noting the position and the number of
2869  * characters to get to the next tab stop.  This information is kept to
2870  * make manipulating the field (scrolling and so on) easier to handle.
2871  */
2872 void
2873 _formi_calculate_tabs(FIELD *field, unsigned row)
2874 {
2875 	_formi_tab_t *ts = field->lines[row].tabs, *old_ts = NULL, **tsp;
2876 	int i, j;
2877 
2878 	  /*
2879 	   * If the line already has tabs then invalidate them by
2880 	   * walking the list and killing the in_use flag.
2881 	   */
2882 	for (; ts != NULL; ts = ts->fwd)
2883 		ts->in_use = FALSE;
2884 
2885 
2886 	  /*
2887 	   * Now look for tabs in the row and record the info...
2888 	   */
2889 	tsp = &field->lines[row].tabs;
2890 	for (i = field->lines[row].start, j = 0; i <= field->lines[row].end;
2891 	     i++, j++) {
2892 		if (field->buffers[0].string[i] == '\t') {
2893 			if (*tsp == NULL) {
2894 				if ((*tsp = (_formi_tab_t *)
2895 				     malloc(sizeof(_formi_tab_t))) == NULL)
2896 					return;
2897 				(*tsp)->back = old_ts;
2898 				(*tsp)->fwd = NULL;
2899 			}
2900 
2901 			(*tsp)->in_use = TRUE;
2902 			(*tsp)->pos = i - field->lines[row].start;
2903 			(*tsp)->size = 8 - (j % 8);
2904 			j += (*tsp)->size - 1;
2905 			old_ts = *tsp;
2906 			tsp = &(*tsp)->fwd;
2907 		}
2908 	}
2909 }
2910 
2911 /*
2912  * Return the size of the tab padding for a tab character at the given
2913  * position.  Return 1 if there is not a tab char entry matching the
2914  * given location.
2915  */
2916 static int
2917 tab_size(FIELD *field, unsigned int offset, unsigned int i)
2918 {
2919 	int row;
2920 	_formi_tab_t *ts;
2921 
2922 	row = find_cur_line(field, offset + i);
2923 	ts = field->lines[row].tabs;
2924 
2925 	while ((ts != NULL) && (ts->pos != i))
2926 		ts = ts->fwd;
2927 
2928 	if (ts == NULL)
2929 		return 1;
2930 	else
2931 		return ts->size;
2932 }
2933 
2934 /*
2935  * Find the character offset that corresponds to longest tab expanded
2936  * string that will fit into the given window.  Walk the string backwards
2937  * evaluating the sizes of any tabs that are in the string.  Note that
2938  * using this function on a multi-line window will produce undefined
2939  * results - it is really only required for a single row field.
2940  */
2941 static int
2942 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window)
2943 {
2944 	int scroll_amt, i;
2945 	_formi_tab_t *ts;
2946 
2947 	  /* first find the last tab */
2948 	ts = field->lines[0].tabs;
2949 
2950 	  /*
2951 	   * unless there are no tabs - just return the window size,
2952 	   * if there is enough room, otherwise 0.
2953 	   */
2954 	if (ts == NULL) {
2955 		if (field->buffers[0].length < window)
2956 			return 0;
2957 		else
2958 			return field->buffers[0].length - window + 1;
2959 	}
2960 
2961 	while ((ts->fwd != NULL) && (ts->fwd->in_use == TRUE))
2962 		ts = ts->fwd;
2963 
2964 	  /*
2965 	   * now walk backwards finding the first tab that is to the
2966 	   * left of our starting pos.
2967 	   */
2968 	while ((ts != NULL) && (ts->in_use == TRUE) && (ts->pos > pos))
2969 		ts = ts->back;
2970 
2971 	scroll_amt = 0;
2972 	for (i = pos; i >= 0; i--) {
2973 		if (field->buffers[0].string[i] == '\t') {
2974 #ifdef DEBUG
2975 			assert((ts != NULL) && (ts->in_use == TRUE));
2976 #endif
2977 			if (ts->pos == i) {
2978 				if ((scroll_amt + ts->size) > window) {
2979 					break;
2980 				}
2981 				scroll_amt += ts->size;
2982 				ts = ts->back;
2983 			}
2984 #ifdef DEBUG
2985 			else
2986 				assert(ts->pos == i);
2987 #endif
2988 		} else {
2989 			scroll_amt++;
2990 			if (scroll_amt > window)
2991 				break;
2992 		}
2993 	}
2994 
2995 	return ++i;
2996 }
2997 
2998 /*
2999  * Return the position of the last character that will fit into the
3000  * given width after tabs have been expanded for a given row of a given
3001  * field.
3002  */
3003 static unsigned int
3004 tab_fit_len(FIELD *field, unsigned int row, unsigned int width)
3005 {
3006 	unsigned int pos, len, row_pos;
3007 	_formi_tab_t *ts;
3008 
3009 	ts = field->lines[row].tabs;
3010 	pos = field->lines[row].start;
3011 	len = 0;
3012 	row_pos = 0;
3013 
3014 	while ((len < width) && (pos < field->buffers[0].length)) {
3015 		if (field->buffers[0].string[pos] == '\t') {
3016 #ifdef DEBUG
3017 			assert((ts != NULL) && (ts->in_use == TRUE));
3018 #endif
3019 			if (ts->pos == row_pos) {
3020 				if ((len + ts->size) > width)
3021 					break;
3022 				len += ts->size;
3023 				ts = ts->fwd;
3024 			}
3025 #ifdef DEBUG
3026 			else
3027 				assert(ts->pos == row_pos);
3028 #endif
3029 		} else
3030 			len++;
3031 		pos++;
3032 		row_pos++;
3033 	}
3034 
3035 	if (pos > 0)
3036 		pos--;
3037 	return pos;
3038 }
3039