xref: /netbsd/lib/libform/internals.c (revision c4a72b64)
1 /*	$NetBSD: internals.c,v 1.28 2002/08/07 11:05:10 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 _formi_set_cursor_xpos(FIELD *field, int no_scroll);
97 static int
98 find_sow(char *str, unsigned int offset);
99 static int
100 find_cur_line(FIELD *cur, unsigned pos);
101 static int
102 split_line(FIELD *field, unsigned pos);
103 static void
104 bump_lines(FIELD *field, int pos, int amt, bool do_len);
105 static bool
106 check_field_size(FIELD *field);
107 static int
108 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c);
109 static int
110 tab_size(FIELD *field, unsigned int offset, unsigned int i);
111 static unsigned int
112 tab_fit_len(FIELD *field, unsigned int row, unsigned int len);
113 static int
114 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window);
115 
116 
117 /*
118  * Initialise the row offset for a field, depending on the type of
119  * field it is and the type of justification used.  The justification
120  * is only used on static single line fields, everything else will
121  * have the cursor_xpos set to 0.
122  */
123 void
124 _formi_init_field_xpos(FIELD *field)
125 {
126 	  /* not static or is multi-line which are not justified, so 0 it is */
127 	if (((field->opts & O_STATIC) != O_STATIC) ||
128 	    ((field->rows + field->nrows) != 1)) {
129 		field->cursor_xpos = 0;
130 		return;
131 	}
132 
133 	switch (field->justification) {
134 	case JUSTIFY_RIGHT:
135 		field->cursor_xpos = field->cols - 1;
136 		break;
137 
138 	case JUSTIFY_CENTER:
139 		field->cursor_xpos = (field->cols - 1) / 2;
140 		break;
141 
142 	default: /* assume left justify */
143 		field->cursor_xpos = 0;
144 		break;
145 	}
146 }
147 
148 
149 /*
150  * Open the debug file if it is not already open....
151  */
152 #ifdef DEBUG
153 int
154 _formi_create_dbg_file(void)
155 {
156 	if (dbg == NULL) {
157 		dbg = fopen("___form_dbg.out", "w");
158 		if (dbg == NULL) {
159 			fprintf(stderr, "Cannot open debug file!\n");
160 			return E_SYSTEM_ERROR;
161 		}
162 	}
163 
164 	return E_OK;
165 }
166 #endif
167 
168 /*
169  * Bump the lines array elements in the given field by the given amount.
170  * The row to start acting on can either be inferred from the given position
171  * or if the special value _FORMI_USE_CURRENT is set then the row will be
172  * the row the cursor is currently on.
173  */
174 static void
175 bump_lines(FIELD *field, int pos, int amt, bool do_len)
176 {
177 	int i, row, old_len;
178 #ifdef DEBUG
179 	int dbg_ok = FALSE;
180 #endif
181 
182 	if (pos == _FORMI_USE_CURRENT)
183 		row = field->start_line + field->cursor_ypos;
184 	else
185 		row = find_cur_line(field, (unsigned) pos);
186 
187 #ifdef DEBUG
188 	if (_formi_create_dbg_file() == E_OK) {
189 		dbg_ok = TRUE;
190 		fprintf(dbg, "bump_lines: bump starting at row %d\n", row);
191 		fprintf(dbg,
192 			"bump_lines: len from %d to %d, end from %d to %d\n",
193 			field->lines[row].length,
194 			field->lines[row].length + amt,
195 			field->lines[row].end, field->lines[row].end + amt);
196 	}
197 #endif
198 
199 	if (((int)field->lines[row].length + amt) < 0) {
200 		field->lines[row].length = 0;
201 		old_len = 0;
202 	} else {
203 		old_len = field->lines[row].length;
204 		if (do_len == TRUE) {
205 			field->lines[row].length =
206 				_formi_tab_expanded_length(
207 					&field->buffers[0].string[
208 						field->lines[row].start], 0,
209 					field->lines[row].end + amt
210 					    -field->lines[row].start);
211 		}
212 	}
213 
214 	if (old_len > 0) {
215 		if ((amt < 0) && (- amt > field->lines[row].end))
216 			field->lines[row].end = field->lines[row].start;
217 		else
218 			field->lines[row].end += amt;
219 	} else
220 		field->lines[row].end = field->lines[row].start;
221 
222 #ifdef DEBUG
223 	if (dbg_ok)
224 		fprintf(dbg, "bump_lines: expanded length %d\n",
225 			field->lines[row].length);
226 #endif
227 
228 	for (i = row + 1; i < field->row_count; i++) {
229 #ifdef DEBUG
230 		if (dbg_ok) {
231 			fprintf(dbg,
232 		"bump_lines: row %d: len from %d to %d, end from %d to %d\n",
233 				i, field->lines[i].start,
234 				field->lines[i].start + amt,
235 				field->lines[i].end,
236 				field->lines[i].end + amt);
237 		}
238 		fflush(dbg);
239 #endif
240 		field->lines[i].start += amt;
241 		field->lines[i].end += amt;
242 		field->lines[i].length = _formi_tab_expanded_length(
243 			&field->buffers[0].string[field->lines[i].start],
244 			0, field->lines[i].end - field->lines[i].start);
245 #ifdef DEBUG
246 		if (dbg_ok) {
247 			fprintf(dbg,
248 				"bump_lines: row %d, expanded length %d\n",
249 				i, field->lines[i].length);
250 		}
251 #endif
252 	}
253 }
254 
255 /*
256  * Check the sizing of the field, if the maximum size is set for a
257  * dynamic field then check that the number of rows or columns does
258  * not exceed the set maximum.  The decision to check the rows or
259  * columns is made on the basis of how many rows are in the field -
260  * one row means the max applies to the number of columns otherwise it
261  * applies to the number of rows.  If the row/column count is less
262  * than the maximum then return TRUE.
263  *
264  */
265 static bool
266 check_field_size(FIELD *field)
267 {
268 	if ((field->opts & O_STATIC) != O_STATIC) {
269 		  /* dynamic field */
270 		if (field->max == 0) /* unlimited */
271 			return TRUE;
272 
273 		if (field->rows == 1) {
274 			return (field->buffers[0].length < field->max);
275 		} else {
276 			return (field->row_count <= field->max);
277 		}
278 	} else {
279 		if ((field->rows + field->nrows) == 1) {
280 			return (field->buffers[0].length <= field->cols);
281 		} else {
282 			return (field->row_count <= (field->rows
283 						     + field->nrows));
284 		}
285 	}
286 }
287 
288 /*
289  * Set the form's current field to the first valid field on the page.
290  * Assume the fields have been sorted and stitched.
291  */
292 int
293 _formi_pos_first_field(FORM *form)
294 {
295 	FIELD *cur;
296 	int old_page;
297 
298 	old_page = form->page;
299 
300 	  /* scan forward for an active page....*/
301 	while (form->page_starts[form->page].in_use == 0) {
302 		form->page++;
303 		if (form->page > form->max_page) {
304 			form->page = old_page;
305 			return E_REQUEST_DENIED;
306 		}
307 	}
308 
309 	  /* then scan for a field we can use */
310 	cur = form->fields[form->page_starts[form->page].first];
311 	while ((cur->opts & (O_VISIBLE | O_ACTIVE))
312 	       != (O_VISIBLE | O_ACTIVE)) {
313 		cur = CIRCLEQ_NEXT(cur, glue);
314 		if (cur == (void *) &form->sorted_fields) {
315 			form->page = old_page;
316 			return E_REQUEST_DENIED;
317 		}
318 	}
319 
320 	form->cur_field = cur->index;
321 	return E_OK;
322 }
323 
324 /*
325  * Set the field to the next active and visible field, the fields are
326  * traversed in index order in the direction given.  If the parameter
327  * use_sorted is TRUE then the sorted field list will be traversed instead
328  * of using the field index.
329  */
330 int
331 _formi_pos_new_field(FORM *form, unsigned direction, unsigned use_sorted)
332 {
333 	FIELD *cur;
334 	int i;
335 
336 	i = form->cur_field;
337 	cur = form->fields[i];
338 
339 	do {
340 		if (direction == _FORMI_FORWARD) {
341 			if (use_sorted == TRUE) {
342 				if ((form->wrap == FALSE) &&
343 				    (cur == CIRCLEQ_LAST(&form->sorted_fields)))
344 					return E_REQUEST_DENIED;
345 				cur = CIRCLEQ_NEXT(cur, glue);
346 				i = cur->index;
347 			} else {
348 				if ((form->wrap == FALSE) &&
349 				    ((i + 1) >= form->field_count))
350 					return E_REQUEST_DENIED;
351 				i++;
352 				if (i >= form->field_count)
353 					i = 0;
354 			}
355 		} else {
356 			if (use_sorted == TRUE) {
357 				if ((form->wrap == FALSE) &&
358 				    (cur == CIRCLEQ_FIRST(&form->sorted_fields)))
359 					return E_REQUEST_DENIED;
360 				cur = CIRCLEQ_PREV(cur, glue);
361 				i = cur->index;
362 			} else {
363 				if ((form->wrap == FALSE) && (i <= 0))
364 					return E_REQUEST_DENIED;
365 				i--;
366 				if (i < 0)
367 					i = form->field_count - 1;
368 			}
369 		}
370 
371 		if ((form->fields[i]->opts & (O_VISIBLE | O_ACTIVE))
372 			== (O_VISIBLE | O_ACTIVE)) {
373 			form->cur_field = i;
374 			return E_OK;
375 		}
376 	}
377 	while (i != form->cur_field);
378 
379 	return E_REQUEST_DENIED;
380 }
381 
382 /*
383  * Find the line in a field that the cursor is currently on.
384  */
385 static int
386 find_cur_line(FIELD *cur, unsigned pos)
387 {
388 	unsigned row;
389 
390 	  /* if there is only one row then that must be it */
391 	if (cur->row_count == 1)
392 		return 0;
393 
394 	  /* first check if pos is at the end of the string, if this
395 	   * is true then just return the last row since the pos may
396 	   * not have been added to the lines array yet.
397 	   */
398 	if (pos == (cur->buffers[0].length - 1))
399 		return (cur->row_count - 1);
400 
401 	for (row = 0; row < cur->row_count; row++) {
402 		if ((pos >= cur->lines[row].start)
403 		    && (pos <= cur->lines[row].end))
404 			return row;
405 	}
406 
407 #ifdef DEBUG
408 	  /* barf if we get here, this should not be possible */
409 	assert((row != row));
410 #endif
411 	return 0;
412 }
413 
414 
415 /*
416  * Word wrap the contents of the field's buffer 0 if this is allowed.
417  * If the wrap is successful, that is, the row count nor the buffer
418  * size is exceeded then the function will return E_OK, otherwise it
419  * will return E_REQUEST_DENIED.
420  */
421 int
422 _formi_wrap_field(FIELD *field, unsigned int loc)
423 {
424 	char *str;
425 	int width, row, start_row;
426 	unsigned int pos;
427 
428 	str = field->buffers[0].string;
429 
430 	if ((field->opts & O_STATIC) == O_STATIC) {
431 		if ((field->rows + field->nrows) == 1) {
432 			return E_OK; /* cannot wrap a single line */
433 		}
434 		width = field->cols;
435 	} else {
436 		  /* if we are limited to one line then don't try to wrap */
437 		if ((field->drows + field->nrows) == 1) {
438 			return E_OK;
439 		}
440 
441 		  /*
442 		   * hueristic - if a dynamic field has more than one line
443 		   * on the screen then the field grows rows, otherwise
444 		   * it grows columns, effectively a single line field.
445 		   * This is documented AT&T behaviour.
446 		   */
447 		if (field->rows > 1) {
448 			width = field->cols;
449 		} else {
450 			return E_OK;
451 		}
452 	}
453 
454 	start_row = find_cur_line(field, loc);
455 
456 	  /* if we are not at the top of the field then back up one
457 	   * row because we may be able to merge the current row into
458 	   * the one above.
459 	   */
460 	if (start_row > 0)
461 		start_row--;
462 
463 	for (row = start_row; row < field->row_count; row++) {
464 	  AGAIN:
465 		pos = field->lines[row].end;
466 		if (field->lines[row].length < width) {
467 			  /* line may be too short, try joining some lines */
468 
469 			if ((((int) field->row_count) - 1) == row) {
470 				/* if this is the last row then don't
471 				 * wrap
472 				 */
473 				continue;
474 			}
475 
476 			if (_formi_join_line(field, (unsigned int) pos,
477 					     JOIN_NEXT_NW) == E_OK) {
478 				goto AGAIN;
479 			} else
480 				break;
481 		} else {
482 			  /* line is too long, split it - maybe */
483 
484 			  /* first check if we have not run out of room */
485 			if ((field->opts & O_STATIC) == O_STATIC) {
486 				/* check static field */
487 				if ((field->rows + field->nrows - 1) == row)
488 					return E_REQUEST_DENIED;
489 			} else {
490 				/* check dynamic field */
491 				if ((field->max != 0)
492 				    && ((field->max - 1) == row))
493 					return E_REQUEST_DENIED;
494 			}
495 
496 			  /*
497 			   * split on first whitespace before current word
498 			   * if the line has tabs we need to work out where
499 			   * the field border lies when the tabs are expanded.
500 			   */
501 			if (field->lines[row].tabs == NULL) {
502 				pos = width + field->lines[row].start - 1;
503 				if (pos >= field->buffers[0].length)
504 					pos = field->buffers[0].length - 1;
505 			} else {
506 				pos = tab_fit_len(field, (unsigned) row,
507 						  field->cols);
508 			}
509 
510 
511 			if ((!isblank(str[pos])) &&
512 			    ((field->opts & O_WRAP) == O_WRAP)) {
513 				if (!isblank(str[pos - 1]))
514 					pos = find_sow(str,
515 						       (unsigned int) pos);
516 				/*
517 				 * If we cannot split the line then return
518 				 * NO_ROOM so the driver can tell that it
519 				 * should not autoskip (if that is enabled)
520 				 */
521 				if ((pos == 0) || (!isblank(str[pos - 1]))
522 				    || ((pos <= field->lines[row].start)
523 					&& (field->buffers[0].length
524 					    >= (width - 1
525 						+ field->lines[row].start)))) {
526 					return E_NO_ROOM;
527 				}
528 			}
529 
530 			  /* if we are at the end of the string and it has
531 			   * a trailing blank, don't wrap the blank.
532 			   */
533 			if ((pos == field->buffers[0].length - 1) &&
534 			    (isblank(str[pos])) &&
535 			    field->lines[row].length <= field->cols)
536 				continue;
537 
538 			  /*
539 			   * otherwise, if we are still sitting on a
540 			   * blank but not at the end of the line
541 			   * move forward one char so the blank
542 			   * is on the line boundary.
543 			   */
544 			if ((isblank(str[pos])) &&
545 			    (pos != field->buffers[0].length - 1))
546 				pos++;
547 
548 			if (split_line(field, pos) != E_OK) {
549 				return E_REQUEST_DENIED;
550 			}
551 		}
552 	}
553 
554 	return E_OK;
555 }
556 
557 /*
558  * Join the two lines that surround the location pos, the type
559  * variable indicates the direction of the join, JOIN_NEXT will join
560  * the next line to the current line, JOIN_PREV will join the current
561  * line to the previous line, the new lines will be wrapped unless the
562  * _NW versions of the directions are used.  Returns E_OK if the join
563  * was successful or E_REQUEST_DENIED if the join cannot happen.
564  */
565 static int
566 _formi_join_line(FIELD *field, unsigned int pos, int direction)
567 {
568 	unsigned int row, i;
569 	int old_alloced, old_row_count;
570 	struct _formi_field_lines *saved;
571 #ifdef DEBUG
572 	int dbg_ok = FALSE;
573 
574 	if (_formi_create_dbg_file() == E_OK) {
575 		dbg_ok = TRUE;
576 	}
577 #endif
578 
579 	if ((saved = (struct _formi_field_lines *)
580 	     malloc(field->lines_alloced * sizeof(struct _formi_field_lines)))
581 	    == NULL)
582 		return E_REQUEST_DENIED;
583 
584 	bcopy(field->lines, saved,
585 	      field->row_count * sizeof(struct _formi_field_lines));
586 	old_alloced = field->lines_alloced;
587 	old_row_count = field->row_count;
588 
589 	row = find_cur_line(field, pos);
590 
591 #ifdef DEBUG
592 	if (dbg_ok == TRUE) {
593 		fprintf(dbg, "join_line: working on row %d, row_count = %d\n",
594 			row, field->row_count);
595 	}
596 #endif
597 
598 	if ((direction == JOIN_NEXT) || (direction == JOIN_NEXT_NW)) {
599 		  /* see if there is another line following... */
600 		if (row == (field->row_count - 1)) {
601 			free(saved);
602 			return E_REQUEST_DENIED;
603 		}
604 
605 #ifdef DEBUG
606 		if (dbg_ok == TRUE) {
607 			fprintf(dbg,
608 			"join_line: join_next before end = %d, length = %d",
609 				field->lines[row].end,
610 				field->lines[row].length);
611 			fprintf(dbg,
612 				" :: next row end = %d, length = %d\n",
613 				field->lines[row + 1].end,
614 				field->lines[row + 1].length);
615 		}
616 #endif
617 
618 		field->lines[row].end = field->lines[row + 1].end;
619 		field->lines[row].length =
620 			_formi_tab_expanded_length(field->buffers[0].string,
621 					    field->lines[row].start,
622 					    field->lines[row].end);
623 		_formi_calculate_tabs(field, row);
624 
625 		  /* shift all the remaining lines up.... */
626 		for (i = row + 2; i < field->row_count; i++)
627 			field->lines[i - 1] = field->lines[i];
628 	} else {
629 		if ((pos == 0) || (row == 0)) {
630 			free(saved);
631 			return E_REQUEST_DENIED;
632 		}
633 
634 #ifdef DEBUG
635 		if (dbg_ok == TRUE) {
636 			fprintf(dbg,
637 			"join_line: join_prev before end = %d, length = %d",
638 				field->lines[row].end,
639 				field->lines[row].length);
640 			fprintf(dbg,
641 				" :: prev row end = %d, length = %d\n",
642 				field->lines[row - 1].end,
643 				field->lines[row - 1].length);
644 		}
645 #endif
646 
647 		field->lines[row - 1].end = field->lines[row].end;
648 		field->lines[row - 1].length =
649 			_formi_tab_expanded_length(field->buffers[0].string,
650 					    field->lines[row - 1].start,
651 					    field->lines[row].end);
652 		  /* shift all the remaining lines up */
653 		for (i = row + 1; i < field->row_count; i++)
654 			field->lines[i - 1] = field->lines[i];
655 	}
656 
657 #ifdef DEBUG
658 	if (dbg_ok == TRUE) {
659 		fprintf(dbg,
660 			"join_line: exit end = %d, length = %d\n",
661 			field->lines[row].end, field->lines[row].length);
662 	}
663 #endif
664 
665 	field->row_count--;
666 
667 	  /* wrap the field if required, if this fails undo the change */
668 	if ((direction == JOIN_NEXT) || (direction == JOIN_PREV)) {
669 		if (_formi_wrap_field(field, (unsigned int) pos) != E_OK) {
670 			free(field->lines);
671 			field->lines = saved;
672 			field->lines_alloced = old_alloced;
673 			field->row_count = old_row_count;
674 			for (i = 0; i < field->row_count; i++)
675 				_formi_calculate_tabs(field, i);
676 			return E_REQUEST_DENIED;
677 		}
678 	}
679 
680 	free(saved);
681 	return E_OK;
682 }
683 
684 /*
685  * Split the line at the given position, if possible
686  */
687 static int
688 split_line(FIELD *field, unsigned pos)
689 {
690 	struct _formi_field_lines *new_lines;
691 	unsigned int row, i;
692 #ifdef DEBUG
693 	short dbg_ok = FALSE;
694 #endif
695 
696 	if (pos == 0)
697 		return E_REQUEST_DENIED;
698 
699 #ifdef DEBUG
700 	if (_formi_create_dbg_file() == E_OK) {
701 		fprintf(dbg, "split_line: splitting line at %d\n", pos);
702 		dbg_ok = TRUE;
703 	}
704 #endif
705 
706 	if ((field->row_count + 1) > field->lines_alloced) {
707 		if ((new_lines = (struct _formi_field_lines *)
708 		     realloc(field->lines, (field->row_count + 1)
709 			     * sizeof(struct _formi_field_lines))) == NULL)
710 			return E_SYSTEM_ERROR;
711 		field->lines = new_lines;
712 		field->lines_alloced++;
713 	}
714 
715 	row = find_cur_line(field, pos);
716 #ifdef DEBUG
717 	if (dbg_ok == TRUE) {
718 		fprintf(dbg,
719 	"split_line: enter: lines[%d].end = %d, lines[%d].length = %d\n",
720 			row, field->lines[row].end, row,
721 			field->lines[row].length);
722 	}
723 
724 	assert(((field->lines[row].end < INT_MAX) &&
725 		(field->lines[row].length < INT_MAX) &&
726 		(field->lines[row].length > 0)));
727 
728 #endif
729 
730 	  /* if asked to split right where the line already starts then
731 	   * just return - nothing to do.
732 	   */
733 	if (field->lines[row].start == pos)
734 		return E_OK;
735 
736 	for (i = field->row_count - 1; i > row; i--) {
737 		field->lines[i + 1] = field->lines[i];
738 	}
739 
740 	field->lines[row + 1].end = field->lines[row].end;
741 	field->lines[row].end = pos - 1;
742 	field->lines[row].length =
743 		_formi_tab_expanded_length(field->buffers[0].string,
744 				    field->lines[row].start,
745 				    field->lines[row].end);
746 	_formi_calculate_tabs(field, row);
747 	field->lines[row + 1].start = pos;
748 	field->lines[row + 1].length =
749 		_formi_tab_expanded_length(field->buffers[0].string,
750 				    field->lines[row + 1].start,
751 				    field->lines[row + 1].end);
752 	field->lines[row + 1].tabs = NULL;
753 	_formi_calculate_tabs(field, row + 1);
754 
755 #ifdef DEBUG
756 	assert(((field->lines[row + 1].end < INT_MAX) &&
757 		(field->lines[row].end < INT_MAX) &&
758 		(field->lines[row].length < INT_MAX) &&
759 		(field->lines[row + 1].start < INT_MAX) &&
760 		(field->lines[row + 1].length < INT_MAX) &&
761 		(field->lines[row].length > 0) &&
762 		(field->lines[row + 1].length > 0)));
763 
764 	if (dbg_ok == TRUE) {
765 		fprintf(dbg,
766 	"split_line: exit: lines[%d].end = %d, lines[%d].length = %d, ",
767 			row, field->lines[row].end, row,
768 			field->lines[row].length);
769 		fprintf(dbg, "lines[%d].start = %d, lines[%d].end = %d, ",
770 			row + 1, field->lines[row + 1].start, row + 1,
771 			field->lines[row + 1].end);
772 		fprintf(dbg, "lines[%d].length = %d, row_count = %d\n",
773 			row + 1, field->lines[row + 1].length,
774 			field->row_count + 1);
775 	}
776 #endif
777 
778 	field->row_count++;
779 
780 #ifdef DEBUG
781 	if (dbg_ok == TRUE) {
782 		bump_lines(field, 0, 0, FALSE); /* will report line data for us */
783 	}
784 #endif
785 
786 	return E_OK;
787 }
788 
789 /*
790  * skip the blanks in the given string, start at the index start and
791  * continue forward until either the end of the string or a non-blank
792  * character is found.  Return the index of either the end of the string or
793  * the first non-blank character.
794  */
795 unsigned
796 _formi_skip_blanks(char *string, unsigned int start)
797 {
798 	unsigned int i;
799 
800 	i = start;
801 
802 	while ((string[i] != '\0') && isblank(string[i]))
803 		i++;
804 
805 	return i;
806 }
807 
808 /*
809  * Return the index of the top left most field of the two given fields.
810  */
811 static int
812 _formi_top_left(FORM *form, int a, int b)
813 {
814 	  /* lower row numbers always win here.... */
815 	if (form->fields[a]->form_row < form->fields[b]->form_row)
816 		return a;
817 
818 	if (form->fields[a]->form_row > form->fields[b]->form_row)
819 		return b;
820 
821 	  /* rows must be equal, check columns */
822 	if (form->fields[a]->form_col < form->fields[b]->form_col)
823 		return a;
824 
825 	if (form->fields[a]->form_col > form->fields[b]->form_col)
826 		return b;
827 
828 	  /* if we get here fields must be in exactly the same place, punt */
829 	return a;
830 }
831 
832 /*
833  * Return the index to the field that is the bottom-right-most of the
834  * two given fields.
835  */
836 static int
837 _formi_bottom_right(FORM *form, int a, int b)
838 {
839 	  /* check the rows first, biggest row wins */
840 	if (form->fields[a]->form_row > form->fields[b]->form_row)
841 		return a;
842 	if (form->fields[a]->form_row < form->fields[b]->form_row)
843 		return b;
844 
845 	  /* rows must be equal, check cols, biggest wins */
846 	if (form->fields[a]->form_col > form->fields[b]->form_col)
847 		return a;
848 	if (form->fields[a]->form_col < form->fields[b]->form_col)
849 		return b;
850 
851 	  /* fields in the same place, punt */
852 	return a;
853 }
854 
855 /*
856  * Find the end of the current word in the string str, starting at
857  * offset - the end includes any trailing whitespace.  If the end of
858  * the string is found before a new word then just return the offset
859  * to the end of the string.
860  */
861 static int
862 find_eow(char *str, unsigned int offset)
863 {
864 	int start;
865 
866 	start = offset;
867 	  /* first skip any non-whitespace */
868 	while ((str[start] != '\0') && !isblank(str[start]))
869 		start++;
870 
871 	  /* see if we hit the end of the string */
872 	if (str[start] == '\0')
873 		return start;
874 
875 	  /* otherwise skip the whitespace.... */
876 	while ((str[start] != '\0') && isblank(str[start]))
877 		start++;
878 
879 	return start;
880 }
881 
882 /*
883  * Find the beginning of the current word in the string str, starting
884  * at offset.
885  */
886 static int
887 find_sow(char *str, unsigned int offset)
888 {
889 	int start;
890 
891 	start = offset;
892 
893 	if (start > 0) {
894 		if (isblank(str[start]) || isblank(str[start - 1])) {
895 			if (isblank(str[start - 1]))
896 				start--;
897 			  /* skip the whitespace.... */
898 			while ((start >= 0) && isblank(str[start]))
899 				start--;
900 		}
901 	}
902 
903 	  /* see if we hit the start of the string */
904 	if (start < 0)
905 		return 0;
906 
907 	  /* now skip any non-whitespace */
908 	while ((start >= 0) && !isblank(str[start]))
909 		start--;
910 
911 	if (start > 0)
912 		start++; /* last loop has us pointing at a space, adjust */
913 
914 	if (start < 0)
915 		start = 0;
916 
917 	return start;
918 }
919 
920 /*
921  * Scroll the field forward the given number of lines.
922  */
923 static void
924 _formi_scroll_fwd(FIELD *field, unsigned int amt)
925 {
926 	  /* check if we have lines to scroll */
927 	if (field->row_count < (field->start_line + field->rows))
928 		return;
929 
930 	field->start_line += min(amt,
931 				 field->row_count - field->start_line
932 				 - field->rows);
933 }
934 
935 /*
936  * Scroll the field backward the given number of lines.
937  */
938 static void
939 _formi_scroll_back(FIELD *field, unsigned int amt)
940 {
941 	if (field->start_line == 0)
942 		return;
943 
944 	field->start_line -= min(field->start_line, amt);
945 }
946 
947 /*
948  * Scroll the field forward the given number of characters.
949  */
950 void
951 _formi_hscroll_fwd(FIELD *field, int unsigned amt)
952 {
953 	unsigned int row, end, scroll_amt, expanded;
954 	_formi_tab_t *ts;
955 
956 	row = field->start_line + field->cursor_ypos;
957 
958 	if ((field->lines[row].tabs == NULL)
959 	    || (field->lines[row].tabs->in_use == FALSE)) {
960 		  /* if the line has no tabs things are easy... */
961 		end =  field->start_char + field->cols + amt - 1;
962 		scroll_amt = amt;
963 		if (end > field->lines[row].end) {
964 			end = field->lines[row].end;
965 			scroll_amt = end - field->start_char - field->cols + 1;
966 		}
967 	} else {
968 		  /*
969 		   * If there are tabs we need to add on the scroll amount,
970 		   * find the last char position that will fit into
971 		   * the field and finally fix up the start_char.  This
972 		   * is a lot of work but handling the case where there
973 		   * are not enough chars to scroll by amt is difficult.
974 		   */
975 		end = field->start_char + field->row_xpos + amt;
976 		if (end >= field->buffers[0].length)
977 			end = field->buffers[0].length - 1;
978 		else {
979 			expanded = _formi_tab_expanded_length(
980 				field->buffers[0].string,
981 				field->start_char + amt,
982 				field->start_char + field->row_xpos + amt);
983 			ts = field->lines[0].tabs;
984 			  /* skip tabs to the lhs of our starting point */
985 			while ((ts != NULL) && (ts->in_use == TRUE)
986 			       && (ts->pos < end))
987 				ts = ts->fwd;
988 
989 			while ((expanded <= field->cols)
990 			       && (end < field->buffers[0].length)) {
991 				if (field->buffers[0].string[end] == '\t') {
992 #ifdef DEBUG
993 					assert((ts != NULL)
994 					       && (ts->in_use == TRUE));
995 #endif
996 					if (ts->pos == end) {
997 						if ((expanded + ts->size)
998 						    > field->cols)
999 							break;
1000 						expanded += ts->size;
1001 						ts = ts->fwd;
1002 					}
1003 #ifdef DEBUG
1004 					else
1005 						assert(ts->pos == end);
1006 #endif
1007 				} else
1008 					expanded++;
1009 				end++;
1010 			}
1011 		}
1012 
1013 		scroll_amt = tab_fit_window(field, end, field->cols);
1014 		if (scroll_amt < field->start_char)
1015 			scroll_amt = 1;
1016 		else
1017 			scroll_amt -= field->start_char;
1018 
1019 		scroll_amt = min(scroll_amt, amt);
1020 	}
1021 
1022 	field->start_char += scroll_amt;
1023 	field->cursor_xpos =
1024 		_formi_tab_expanded_length(field->buffers[0].string,
1025 					   field->start_char,
1026 					   field->row_xpos
1027 					   + field->start_char) - 1;
1028 
1029 }
1030 
1031 /*
1032  * Scroll the field backward the given number of characters.
1033  */
1034 void
1035 _formi_hscroll_back(FIELD *field, unsigned int amt)
1036 {
1037 	field->start_char -= min(field->start_char, amt);
1038 	field->cursor_xpos =
1039 		_formi_tab_expanded_length(field->buffers[0].string,
1040 					   field->start_char,
1041 					   field->row_xpos
1042 					   + field->start_char) - 1;
1043 	if (field->cursor_xpos >= field->cols) {
1044 		field->row_xpos = 0;
1045 		field->cursor_xpos = 0;
1046 	}
1047 }
1048 
1049 /*
1050  * Find the different pages in the form fields and assign the form
1051  * page_starts array with the information to find them.
1052  */
1053 int
1054 _formi_find_pages(FORM *form)
1055 {
1056 	int i, cur_page = 0;
1057 
1058 	if ((form->page_starts = (_FORMI_PAGE_START *)
1059 	     malloc((form->max_page + 1) * sizeof(_FORMI_PAGE_START))) == NULL)
1060 		return E_SYSTEM_ERROR;
1061 
1062 	  /* initialise the page starts array */
1063 	memset(form->page_starts, 0,
1064 	       (form->max_page + 1) * sizeof(_FORMI_PAGE_START));
1065 
1066 	for (i =0; i < form->field_count; i++) {
1067 		if (form->fields[i]->page_break == 1)
1068 			cur_page++;
1069 		if (form->page_starts[cur_page].in_use == 0) {
1070 			form->page_starts[cur_page].in_use = 1;
1071 			form->page_starts[cur_page].first = i;
1072 			form->page_starts[cur_page].last = i;
1073 			form->page_starts[cur_page].top_left = i;
1074 			form->page_starts[cur_page].bottom_right = i;
1075 		} else {
1076 			form->page_starts[cur_page].last = i;
1077 			form->page_starts[cur_page].top_left =
1078 				_formi_top_left(form,
1079 						form->page_starts[cur_page].top_left,
1080 						i);
1081 			form->page_starts[cur_page].bottom_right =
1082 				_formi_bottom_right(form,
1083 						    form->page_starts[cur_page].bottom_right,
1084 						    i);
1085 		}
1086 	}
1087 
1088 	return E_OK;
1089 }
1090 
1091 /*
1092  * Completely redraw the field of the given form.
1093  */
1094 void
1095 _formi_redraw_field(FORM *form, int field)
1096 {
1097 	unsigned int pre, post, flen, slen, i, row, start;
1098 	unsigned int last_row, tab, cpos, len;
1099 	char *str, c;
1100 	FIELD *cur;
1101 #ifdef DEBUG
1102 	char buffer[100];
1103 #endif
1104 
1105 	cur = form->fields[field];
1106 	str = cur->buffers[0].string;
1107 	flen = cur->cols;
1108 	slen = 0;
1109 	start = 0;
1110 
1111 	if ((cur->row_count - cur->start_line) < cur->rows)
1112 		last_row = cur->row_count;
1113 	else
1114 		last_row = cur->start_line + cur->rows;
1115 
1116 	for (row = cur->start_line; row < last_row; row++) {
1117 		wmove(form->scrwin,
1118 		      (int) (cur->form_row + row - cur->start_line),
1119 		      (int) cur->form_col);
1120 		start = cur->lines[row].start;
1121 		if ((cur->rows + cur->nrows) == 1) {
1122 			if ((cur->start_char + cur->cols)
1123 			    >= cur->buffers[0].length)
1124 				len = cur->buffers[0].length;
1125 			else
1126 				len = cur->cols + cur->start_char;
1127 			slen = _formi_tab_expanded_length(
1128 				cur->buffers[0].string, cur->start_char, len);
1129 			if (slen > cur->cols)
1130 				slen = cur->cols;
1131 			slen += cur->start_char;
1132 		} else
1133 			slen = cur->lines[row].length;
1134 
1135 		if ((cur->opts & O_STATIC) == O_STATIC) {
1136 			switch (cur->justification) {
1137 			case JUSTIFY_RIGHT:
1138 				post = 0;
1139 				if (flen < slen)
1140 					pre = 0;
1141 				else
1142 					pre = flen - slen;
1143 				break;
1144 
1145 			case JUSTIFY_CENTER:
1146 				if (flen < slen) {
1147 					pre = 0;
1148 					post = 0;
1149 				} else {
1150 					pre = flen - slen;
1151 					post = pre = pre / 2;
1152 					  /* get padding right if
1153                                              centring is not even */
1154 					if ((post + pre + slen) < flen)
1155 						post++;
1156 				}
1157 				break;
1158 
1159 			case NO_JUSTIFICATION:
1160 			case JUSTIFY_LEFT:
1161 			default:
1162 				pre = 0;
1163 				if (flen <= slen)
1164 					post = 0;
1165 				else {
1166 					post = flen - slen;
1167 					if (post > flen)
1168 						post = flen;
1169 				}
1170 				break;
1171 			}
1172 		} else {
1173 			  /* dynamic fields are not justified */
1174 			pre = 0;
1175 			if (flen <= slen)
1176 				post = 0;
1177 			else {
1178 				post = flen - slen;
1179 				if (post > flen)
1180 					post = flen;
1181 			}
1182 
1183 			  /* but they do scroll.... */
1184 
1185 			if (pre > cur->start_char - start)
1186 				pre = pre - cur->start_char + start;
1187 			else
1188 				pre = 0;
1189 
1190 			if (slen > cur->start_char) {
1191 				slen -= cur->start_char;
1192 				if (slen > flen)
1193 					post = 0;
1194 				else
1195 					post = flen - slen;
1196 
1197 				if (post > flen)
1198 					post = flen;
1199 			} else {
1200 				slen = 0;
1201 				post = flen - pre;
1202 			}
1203 		}
1204 
1205 		if (form->cur_field == field)
1206 			wattrset(form->scrwin, cur->fore);
1207 		else
1208 			wattrset(form->scrwin, cur->back);
1209 
1210 #ifdef DEBUG
1211 		if (_formi_create_dbg_file() == E_OK) {
1212 			fprintf(dbg,
1213   "redraw_field: start=%d, pre=%d, slen=%d, flen=%d, post=%d, start_char=%d\n",
1214 				start, pre, slen, flen, post, cur->start_char);
1215 			if (str != NULL) {
1216 				strncpy(buffer,
1217 					&str[cur->start_char
1218 					    + cur->lines[row].start], flen);
1219 			} else {
1220 				strcpy(buffer, "(null)");
1221 			}
1222 			buffer[flen] = '\0';
1223 			fprintf(dbg, "redraw_field: %s\n", buffer);
1224 		}
1225 #endif
1226 
1227 		for (i = start + cur->start_char; i < pre; i++)
1228 			waddch(form->scrwin, cur->pad);
1229 
1230 #ifdef DEBUG
1231 		fprintf(dbg, "redraw_field: will add %d chars\n",
1232 			min(slen, flen));
1233 #endif
1234 		str = &cur->buffers[0].string[cur->start_char
1235 					     + cur->lines[row].start];
1236 
1237 		for (i = 0, cpos = cur->start_char; i < min(slen, flen);
1238 		     i++, str++, cpos++)
1239 		{
1240 			c = *str;
1241 			tab = 0; /* just to shut gcc up */
1242 #ifdef DEBUG
1243 			fprintf(dbg, "adding char str[%d]=%c\n",
1244 				cpos + cur->start_char + cur->lines[row].start,
1245 				c);
1246 #endif
1247 			if (((cur->opts & O_PUBLIC) != O_PUBLIC)) {
1248 				if (c == '\t')
1249 					tab = add_tab(form, cur, row,
1250 						      cpos, cur->pad);
1251 				else
1252 					waddch(form->scrwin, cur->pad);
1253 			} else if ((cur->opts & O_VISIBLE) == O_VISIBLE) {
1254 				if (c == '\t')
1255 					tab = add_tab(form, cur, row, cpos,
1256 						      ' ');
1257 				else
1258 					waddch(form->scrwin, c);
1259 			} else {
1260 				if (c == '\t')
1261 					tab = add_tab(form, cur, row, cpos,
1262 						      ' ');
1263 				else
1264 					waddch(form->scrwin, ' ');
1265 			}
1266 
1267 			  /*
1268 			   * If we have had a tab then skip forward
1269 			   * the requisite number of chars to keep
1270 			   * things in sync.
1271 			   */
1272 			if (c == '\t')
1273 				i += tab - 1;
1274 		}
1275 
1276 		for (i = 0; i < post; i++)
1277 			waddch(form->scrwin, cur->pad);
1278 	}
1279 
1280 	for (row = cur->row_count - cur->start_line; row < cur->rows; row++) {
1281 		wmove(form->scrwin, (int) (cur->form_row + row),
1282 		      (int) cur->form_col);
1283 
1284 		if (form->cur_field == field)
1285 			wattrset(form->scrwin, cur->fore);
1286 		else
1287 			wattrset(form->scrwin, cur->back);
1288 
1289 		for (i = 0; i < cur->cols; i++) {
1290 			waddch(form->scrwin, cur->pad);
1291 		}
1292 	}
1293 
1294 	wattrset(form->scrwin, cur->back);
1295 	return;
1296 }
1297 
1298 /*
1299  * Add the correct number of the given character to simulate a tab
1300  * in the field.
1301  */
1302 static int
1303 add_tab(FORM *form, FIELD *field, unsigned row, unsigned int i, char c)
1304 {
1305 	int j;
1306 	_formi_tab_t *ts = field->lines[row].tabs;
1307 
1308 	while ((ts != NULL) && (ts->pos != i))
1309 		ts = ts->fwd;
1310 
1311 #ifdef DEBUG
1312 	assert(ts != NULL);
1313 #endif
1314 
1315 	for (j = 0; j < ts->size; j++)
1316 		waddch(form->scrwin, c);
1317 
1318 	return ts->size;
1319 }
1320 
1321 
1322 /*
1323  * Display the fields attached to the form that are on the current page
1324  * on the screen.
1325  *
1326  */
1327 int
1328 _formi_draw_page(FORM *form)
1329 {
1330 	int i;
1331 
1332 	if (form->page_starts[form->page].in_use == 0)
1333 		return E_BAD_ARGUMENT;
1334 
1335 	wclear(form->scrwin);
1336 
1337 	for (i = form->page_starts[form->page].first;
1338 	     i <= form->page_starts[form->page].last; i++)
1339 		_formi_redraw_field(form, i);
1340 
1341 	return E_OK;
1342 }
1343 
1344 /*
1345  * Add the character c at the position pos in buffer 0 of the given field
1346  */
1347 int
1348 _formi_add_char(FIELD *field, unsigned int pos, char c)
1349 {
1350 	char *new, old_c;
1351 	unsigned int new_size;
1352 	int status;
1353 
1354 	  /*
1355 	   * If buffer has not had a string before, set it to a blank
1356 	   * string.  Everything should flow from there....
1357 	   */
1358 	if (field->buffers[0].string == NULL) {
1359 		set_field_buffer(field, 0, "");
1360 	}
1361 
1362 	if (_formi_validate_char(field, c) != E_OK) {
1363 #ifdef DEBUG
1364 		fprintf(dbg, "add_char: char %c failed char validation\n", c);
1365 #endif
1366 		return E_INVALID_FIELD;
1367 	}
1368 
1369 	if ((c == '\t') && (field->cols <= 8)) {
1370 #ifdef DEBUG
1371 		fprintf(dbg, "add_char: field too small for a tab\n");
1372 #endif
1373 		return E_NO_ROOM;
1374 	}
1375 
1376 #ifdef DEBUG
1377 	fprintf(dbg, "add_char: pos=%d, char=%c\n", pos, c);
1378 	fprintf(dbg, "add_char enter: xpos=%d, row_pos=%d, start=%d\n",
1379 		field->cursor_xpos, field->row_xpos, field->start_char);
1380 	fprintf(dbg, "add_char enter: length=%d(%d), allocated=%d\n",
1381 		field->buffers[0].length, strlen(field->buffers[0].string),
1382 		field->buffers[0].allocated);
1383 	fprintf(dbg, "add_char enter: %s\n", field->buffers[0].string);
1384 	fprintf(dbg, "add_char enter: buf0_status=%d\n", field->buf0_status);
1385 #endif
1386 	if (((field->opts & O_BLANK) == O_BLANK) &&
1387 	    (field->buf0_status == FALSE) &&
1388 	    ((field->row_xpos + field->start_char) == 0)) {
1389 		field->buffers[0].length = 0;
1390 		field->buffers[0].string[0] = '\0';
1391 		pos = 0;
1392 		field->start_char = 0;
1393 		field->start_line = 0;
1394 		field->row_count = 1;
1395 		field->row_xpos = 0;
1396 		field->cursor_ypos = 0;
1397 		field->lines[0].start = 0;
1398 		field->lines[0].end = 0;
1399 		field->lines[0].length = 0;
1400 		_formi_init_field_xpos(field);
1401 	}
1402 
1403 
1404 	if ((field->overlay == 0)
1405 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1406 		  /* first check if the field can have more chars...*/
1407 		if (check_field_size(field) == FALSE)
1408 			return E_REQUEST_DENIED;
1409 
1410 		if (field->buffers[0].length + 1
1411 		    >= field->buffers[0].allocated) {
1412 			new_size = field->buffers[0].allocated + 64
1413 				- (field->buffers[0].allocated % 64);
1414 			if ((new = (char *) realloc(field->buffers[0].string,
1415 						    new_size )) == NULL)
1416 				return E_SYSTEM_ERROR;
1417 			field->buffers[0].allocated = new_size;
1418 			field->buffers[0].string = new;
1419 		}
1420 	}
1421 
1422 	if ((field->overlay == 0) && (field->buffers[0].length > pos)) {
1423 		bcopy(&field->buffers[0].string[pos],
1424 		      &field->buffers[0].string[pos + 1],
1425 		      field->buffers[0].length - pos + 1);
1426 	}
1427 
1428 	old_c = field->buffers[0].string[pos];
1429 	field->buffers[0].string[pos] = c;
1430 	if (pos >= field->buffers[0].length) {
1431 		  /* make sure the string is terminated if we are at the
1432 		   * end of the string, the terminator would be missing
1433 		   * if we are are at the end of the field.
1434 		   */
1435 		field->buffers[0].string[pos + 1] = '\0';
1436 	}
1437 
1438 	  /* only increment the length if we are inserting characters
1439 	   * OR if we are at the end of the field in overlay mode.
1440 	   */
1441 	if ((field->overlay == 0)
1442 	    || ((field->overlay == 1) && (pos >= field->buffers[0].length))) {
1443 		field->buffers[0].length++;
1444 		bump_lines(field, (int) pos, 1, TRUE);
1445 	} else if (field->overlay == 1)
1446 		bump_lines(field, (int) pos, 0, TRUE);
1447 
1448 	new_size = find_cur_line(field, pos);
1449 	_formi_calculate_tabs(field, new_size);
1450 
1451 	  /* wrap the field, if needed */
1452 	status = _formi_wrap_field(field, pos);
1453 
1454 	  /* just in case the row we are on wrapped */
1455 	new_size = find_cur_line(field, pos);
1456 
1457 	  /*
1458 	   * check the wrap worked or that we have not exceeded the
1459 	   * max field size - this can happen if the field is re-wrapped
1460 	   * and the row count is increased past the set limit.
1461 	   */
1462 	if ((status != E_OK) || (check_field_size(field) == FALSE)) {
1463 		if ((field->overlay == 0)
1464 		    || ((field->overlay == 1)
1465 			&& (pos >= field->buffers[0].length))) {
1466 			  /*
1467 			   * wrap failed for some reason, back out the
1468 			   * char insert
1469 			   */
1470 			bcopy(&field->buffers[0].string[pos + 1],
1471 			      &field->buffers[0].string[pos],
1472 			      field->buffers[0].length - pos);
1473 			field->buffers[0].length--;
1474 			bump_lines(field, (int) pos, -1, TRUE);
1475 			if (pos > 0)
1476 				pos--;
1477 		} else if (field->overlay == 1) {
1478 			  /* back out character overlay */
1479 			field->buffers[0].string[pos] = old_c;
1480 		}
1481 
1482 		new_size = find_cur_line(field, pos);
1483 		_formi_calculate_tabs(field, new_size);
1484 
1485 		_formi_wrap_field(field, pos);
1486 		  /*
1487 		   * If we are here then either the status is bad or we
1488 		   * simply ran out of room.  If the status is E_OK then
1489 		   * we ran out of room, let the form driver know this.
1490 		   */
1491 		if (status == E_OK)
1492 			status = E_REQUEST_DENIED;
1493 
1494 	} else {
1495 		field->buf0_status = TRUE;
1496 		if ((field->rows + field->nrows) == 1) {
1497 			field->row_xpos++;
1498 			status = _formi_set_cursor_xpos(field, FALSE);
1499 		} else {
1500 			if (new_size >= field->rows) {
1501 				field->cursor_ypos = field->rows - 1;
1502 				field->start_line = field->row_count
1503 					- field->cursor_ypos - 1;
1504 			} else
1505 				field->cursor_ypos = new_size;
1506 
1507 			if ((field->lines[new_size].start) <= (pos + 1)) {
1508 				field->row_xpos = pos
1509 					- field->lines[new_size].start + 1;
1510 				field->cursor_xpos =
1511 					_formi_tab_expanded_length(
1512 						&field->buffers[0].string[
1513 						    field->lines[new_size].start], 0,
1514 						field->row_xpos - 1);
1515 			} else {
1516 				field->row_xpos = 0;
1517 				field->cursor_xpos = 0;
1518 			}
1519 
1520 			  /*
1521 			   * Annoying corner case - if we are right in
1522 			   * the bottom right corner of the field we
1523 			   * need to scroll the field one line so the
1524 			   * cursor is positioned correctly in the
1525 			   * field.
1526 			   */
1527 			if ((field->cursor_xpos >= field->cols) &&
1528 			    (field->cursor_ypos == (field->rows - 1))) {
1529 				field->cursor_ypos--;
1530 				field->start_line++;
1531 			}
1532 		}
1533 	}
1534 
1535 #ifdef DEBUG
1536 	assert((field->cursor_xpos <= field->cols)
1537 	       && (field->cursor_ypos < 400000)
1538 	       && (field->start_line < 400000));
1539 
1540 	fprintf(dbg, "add_char exit: xpos=%d, row_pos=%d, start=%d\n",
1541 		field->cursor_xpos, field->row_xpos, field->start_char);
1542 	fprintf(dbg, "add_char_exit: length=%d(%d), allocated=%d\n",
1543 		field->buffers[0].length, strlen(field->buffers[0].string),
1544 		field->buffers[0].allocated);
1545 	fprintf(dbg, "add_char exit: ypos=%d, start_line=%d\n",
1546 		field->cursor_ypos, field->start_line);
1547 	fprintf(dbg,"add_char exit: %s\n", field->buffers[0].string);
1548 	fprintf(dbg, "add_char exit: buf0_status=%d\n", field->buf0_status);
1549 	fprintf(dbg, "add_char exit: status = %s\n",
1550 		(status == E_OK)? "OK" : "FAILED");
1551 #endif
1552 	return status;
1553 }
1554 
1555 /*
1556  * Set the position of the cursor on the screen in the row depending on
1557  * where the current position in the string is and the justification
1558  * that is to be applied to the field.  Justification is only applied
1559  * to single row, static fields.
1560  */
1561 static int
1562 _formi_set_cursor_xpos(FIELD *field, int noscroll)
1563 {
1564 	int just, pos;
1565 
1566 	just = field->justification;
1567 	pos = field->start_char + field->row_xpos
1568 	   + field->lines[field->start_line + field->cursor_ypos].start;
1569 
1570 #ifdef DEBUG
1571 	fprintf(dbg,
1572 	  "cursor_xpos enter: pos %d, start_char %d, row_xpos %d, xpos %d\n",
1573 		pos, field->start_char, field->row_xpos, field->cursor_xpos);
1574 #endif
1575 
1576 	  /*
1577 	   * make sure we apply the correct justification to non-static
1578 	   * fields.
1579 	   */
1580 	if (((field->rows + field->nrows) != 1) ||
1581 	    ((field->opts & O_STATIC) != O_STATIC))
1582 		just = JUSTIFY_LEFT;
1583 
1584 	switch (just) {
1585 	case JUSTIFY_RIGHT:
1586 		field->cursor_xpos = field->cols - 1
1587 			- _formi_tab_expanded_length(
1588 				field->buffers[0].string, 0,
1589 				field->buffers[0].length - 1)
1590 			+ _formi_tab_expanded_length(
1591 				field->buffers[0].string, 0,
1592 				field->row_xpos);
1593 		break;
1594 
1595 	case JUSTIFY_CENTER:
1596 		field->cursor_xpos = ((field->cols - 1)
1597 			- _formi_tab_expanded_length(
1598 				field->buffers[0].string, 0,
1599 				field->buffers[0].length - 1) + 1) / 2
1600 			+ _formi_tab_expanded_length(field->buffers[0].string,
1601 						     0, field->row_xpos);
1602 
1603 		if (field->cursor_xpos > (field->cols - 1))
1604 			field->cursor_xpos = (field->cols - 1);
1605 		break;
1606 
1607 	default:
1608 		field->cursor_xpos = _formi_tab_expanded_length(
1609 			field->buffers[0].string,
1610 			field->start_char,
1611 			field->row_xpos	+ field->start_char);
1612 		if ((field->cursor_xpos <= (field->cols - 1)) &&
1613 		    ((field->start_char + field->row_xpos)
1614 		     < field->buffers[0].length))
1615 			field->cursor_xpos--;
1616 
1617 		if (field->cursor_xpos > (field->cols - 1)) {
1618 			if ((field->opts & O_STATIC) == O_STATIC) {
1619 				field->start_char = 0;
1620 
1621 				if (field->row_xpos
1622 				    == (field->buffers[0].length - 1)) {
1623 					field->cursor_xpos = field->cols - 1;
1624 				} else {
1625 					field->cursor_xpos =
1626 						_formi_tab_expanded_length(
1627 						  field->buffers[0].string,
1628 						  field->start_char,
1629 						  field->row_xpos
1630 						    + field->start_char
1631 						  - 1) - 1;
1632 				}
1633 			} else {
1634 				if (noscroll == FALSE) {
1635 					field->start_char =
1636 						tab_fit_window(
1637 							field,
1638 							field->start_char
1639 							+ field->row_xpos,
1640 							field->cols);
1641 					field->row_xpos = pos
1642 						- field->start_char;
1643 					field->cursor_xpos =
1644 						_formi_tab_expanded_length(
1645 						   field->buffers[0].string,
1646 						   field->start_char,
1647 						   field->row_xpos
1648 						      + field->start_char - 1);
1649 				} else {
1650 					field->cursor_xpos = (field->cols - 1);
1651 				}
1652 			}
1653 
1654 		}
1655 		break;
1656 	}
1657 
1658 #ifdef DEBUG
1659 	fprintf(dbg,
1660 	  "cursor_xpos exit: pos %d, start_char %d, row_xpos %d, xpos %d\n",
1661 		pos, field->start_char, field->row_xpos, field->cursor_xpos);
1662 #endif
1663 	return E_OK;
1664 }
1665 
1666 /*
1667  * Manipulate the text in a field, this takes the given form and performs
1668  * the passed driver command on the current text field.  Returns 1 if the
1669  * text field was modified.
1670  */
1671 int
1672 _formi_manipulate_field(FORM *form, int c)
1673 {
1674 	FIELD *cur;
1675 	char *str, saved;
1676 	unsigned int start, end, pos, row, status, old_count, size;
1677 	unsigned int old_xpos, old_row_pos;
1678 	int len;
1679 
1680 	cur = form->fields[form->cur_field];
1681 	if ((cur->buffers[0].string == NULL) || (cur->buffers[0].length == 0))
1682 		return E_REQUEST_DENIED;
1683 
1684 #ifdef DEBUG
1685 	fprintf(dbg, "entry: request is REQ_%s\n", reqs[c - REQ_MIN_REQUEST]);
1686 	fprintf(dbg,
1687 	"entry: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
1688 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
1689 		cur->buffers[0].length,	cur->buffers[0].allocated);
1690 	fprintf(dbg, "entry: start_line=%d, ypos=%d\n", cur->start_line,
1691 		cur->cursor_ypos);
1692 	fprintf(dbg, "entry: string=");
1693 	if (cur->buffers[0].string == NULL)
1694 		fprintf(dbg, "(null)\n");
1695 	else
1696 		fprintf(dbg, "\"%s\"\n", cur->buffers[0].string);
1697 #endif
1698 
1699 	  /* Cannot manipulate a null string! */
1700 	if (cur->buffers[0].string == NULL)
1701 		return E_REQUEST_DENIED;
1702 
1703 	row = cur->start_line + cur->cursor_ypos;
1704 	saved = cur->buffers[0].string[cur->start_char + cur->row_xpos
1705 				      + cur->lines[row].start];
1706 
1707 	switch (c) {
1708 	case REQ_RIGHT_CHAR:
1709 		  /*
1710 		   * The right_char request performs the same function
1711 		   * as the next_char request except that the cursor is
1712 		   * not wrapped if it is at the end of the line, so
1713 		   * check if the cursor is at the end of the line and
1714 		   * deny the request otherwise just fall through to
1715 		   * the next_char request handler.
1716 		   */
1717 		if (cur->cursor_xpos >= cur->cols - 1)
1718 			return E_REQUEST_DENIED;
1719 
1720 		  /* FALLTHRU */
1721 
1722 	case REQ_NEXT_CHAR:
1723 		  /* for a dynamic field allow an offset of one more
1724 		   * char so we can insert chars after end of string.
1725 		   * Static fields cannot do this so deny request if
1726 		   * cursor is at the end of the field.
1727 		   */
1728 		if (((cur->opts & O_STATIC) == O_STATIC) &&
1729 		    (cur->row_xpos == cur->cols - 1) &&
1730 		    ((cur->rows + cur->nrows) == 1))
1731 			return E_REQUEST_DENIED;
1732 
1733 		if ((cur->row_xpos + cur->start_char + 1)
1734 		    > cur->buffers[0].length)
1735 			return E_REQUEST_DENIED;
1736 
1737 		if ((cur->rows + cur->nrows) == 1) {
1738 			cur->row_xpos++;
1739 			_formi_set_cursor_xpos(cur, (c == REQ_RIGHT_CHAR));
1740 		} else {
1741 			if (cur->cursor_xpos >= (cur->lines[row].length - 1)) {
1742 				if (((row + 1) >= cur->row_count) ||
1743 				    (c == REQ_RIGHT_CHAR))
1744 					return E_REQUEST_DENIED;
1745 
1746 				cur->cursor_xpos = 0;
1747 				cur->row_xpos = 0;
1748 				if (cur->cursor_ypos == (cur->rows - 1))
1749 					cur->start_line++;
1750 				else
1751 					cur->cursor_ypos++;
1752 			} else {
1753 				old_xpos = cur->cursor_xpos;
1754 				old_row_pos = cur->row_xpos;
1755 				if (saved == '\t')
1756 					cur->cursor_xpos += tab_size(cur,
1757 							cur->lines[row].start,
1758 							cur->row_xpos);
1759 				else
1760 					cur->cursor_xpos++;
1761 				cur->row_xpos++;
1762 				if (cur->cursor_xpos
1763 				    >= cur->lines[row].length) {
1764 					if (((row + 1) >= cur->row_count) ||
1765 					    (c == REQ_RIGHT_CHAR)) {
1766 						cur->cursor_xpos = old_xpos;
1767 						cur->row_xpos = old_row_pos;
1768 						return E_REQUEST_DENIED;
1769 					}
1770 
1771 					cur->cursor_xpos = 0;
1772 					cur->row_xpos = 0;
1773 					if (cur->cursor_ypos
1774 					    == (cur->rows - 1))
1775 						cur->start_line++;
1776 					else
1777 						cur->cursor_ypos++;
1778 				}
1779 			}
1780 		}
1781 
1782 		break;
1783 
1784 	case REQ_LEFT_CHAR:
1785 		  /*
1786 		   * The behaviour of left_char is the same as prev_char
1787 		   * except that the cursor will not wrap if it has
1788 		   * reached the LHS of the field, so just check this
1789 		   * and fall through if we are not at the LHS.
1790 		   */
1791 		if (cur->cursor_xpos == 0)
1792 			return E_REQUEST_DENIED;
1793 
1794 		  /* FALLTHRU */
1795 	case REQ_PREV_CHAR:
1796 		if ((cur->rows + cur->nrows) == 1) {
1797 			if (cur->row_xpos == 0) {
1798 				if (cur->start_char > 0)
1799 					cur->start_char--;
1800 				else
1801 					return E_REQUEST_DENIED;
1802 			} else {
1803 				cur->row_xpos--;
1804 				_formi_set_cursor_xpos(cur, FALSE);
1805 			}
1806 		} else {
1807 			if ((cur->cursor_xpos == 0) &&
1808 			    (cur->cursor_ypos == 0) &&
1809 			    (cur->start_line == 0))
1810 				return E_REQUEST_DENIED;
1811 
1812 			row = cur->start_line + cur->cursor_ypos;
1813 			pos = cur->lines[row].start + cur->row_xpos;
1814 			if ((pos >= cur->buffers[0].length) && (pos > 0))
1815 				pos--;
1816 
1817 			if (cur->cursor_xpos > 0) {
1818 				if (cur->buffers[0].string[pos] == '\t') {
1819 					size = tab_size(cur,
1820 							cur->lines[row].start,
1821 							pos
1822 							- cur->lines[row].start);
1823 					if (size > cur->cursor_xpos) {
1824 						cur->cursor_xpos = 0;
1825 						cur->row_xpos = 0;
1826 					} else {
1827 						cur->row_xpos--;
1828 						cur->cursor_xpos -= size;
1829 					}
1830 				} else {
1831 					cur->cursor_xpos--;
1832 					cur->row_xpos--;
1833 				}
1834 			} else {
1835 				if (cur->cursor_ypos > 0)
1836 					cur->cursor_ypos--;
1837 				else
1838 					cur->start_line--;
1839 				row = cur->start_line + cur->cursor_ypos;
1840 				cur->cursor_xpos = cur->lines[row].length - 1;
1841 				cur->row_xpos = cur->lines[row].end -
1842 					cur->lines[row].start;
1843 			}
1844 		}
1845 
1846 		break;
1847 
1848 	case REQ_DOWN_CHAR:
1849 		  /*
1850 		   * The down_char request has the same functionality as
1851 		   * the next_line request excepting that the field is not
1852 		   * scrolled if the cursor is at the bottom of the field.
1853 		   * Check to see if the cursor is at the bottom of the field
1854 		   * and if it is then deny the request otherwise fall
1855 		   * through to the next_line handler.
1856 		   */
1857 		if (cur->cursor_ypos >= cur->rows - 1)
1858 			return E_REQUEST_DENIED;
1859 
1860 		  /* FALLTHRU */
1861 
1862 	case REQ_NEXT_LINE:
1863 		if ((cur->start_line + cur->cursor_ypos + 1) >= cur->row_count)
1864 			return E_REQUEST_DENIED;
1865 
1866 		if ((cur->cursor_ypos + 1) >= cur->rows) {
1867 			cur->start_line++;
1868 		} else
1869 			cur->cursor_ypos++;
1870 		row = cur->cursor_ypos + cur->start_line;
1871 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos)
1872 			- cur->lines[row].start;
1873 		cur->cursor_xpos =
1874 			_formi_tab_expanded_length(
1875 				&cur->buffers[0].string[cur->lines[row].start],
1876 				0, cur->row_xpos);
1877 		break;
1878 
1879 	case REQ_UP_CHAR:
1880 		  /*
1881 		   * The up_char request has the same functionality as
1882 		   * the prev_line request excepting the field is not
1883 		   * scrolled, check if the cursor is at the top of the
1884 		   * field, if it is deny the request otherwise fall
1885 		   * through to the prev_line handler.
1886 		   */
1887 		if (cur->cursor_ypos == 0)
1888 			return E_REQUEST_DENIED;
1889 
1890 		  /* FALLTHRU */
1891 
1892 	case REQ_PREV_LINE:
1893 		if (cur->cursor_ypos == 0) {
1894 			if (cur->start_line == 0)
1895 				return E_REQUEST_DENIED;
1896 			cur->start_line--;
1897 		} else
1898 			cur->cursor_ypos--;
1899 		row = cur->cursor_ypos + cur->start_line;
1900 		cur->row_xpos =	tab_fit_len(cur, row, cur->cursor_xpos + 1)
1901 			- cur->lines[row].start;
1902 		cur->cursor_xpos =
1903 			_formi_tab_expanded_length(
1904 				&cur->buffers[0].string[cur->lines[row].start],
1905 				0, cur->row_xpos) - 1;
1906 		break;
1907 
1908 	case REQ_NEXT_WORD:
1909 		start = cur->lines[cur->start_line + cur->cursor_ypos].start
1910 			+ cur->row_xpos + cur->start_char;
1911 		str = cur->buffers[0].string;
1912 
1913 		start = find_eow(str, start);
1914 
1915 		  /* check if we hit the end */
1916 		if (str[start] == '\0')
1917 			return E_REQUEST_DENIED;
1918 
1919 		  /* otherwise we must have found the start of a word...*/
1920 		if ((cur->rows + cur->nrows) == 1) {
1921 			  /* single line field */
1922 			size = _formi_tab_expanded_length(str,
1923 				cur->start_char, start);
1924 			if (size < cur->cols) {
1925 				cur->row_xpos = start - cur->start_char;
1926 			} else {
1927 				cur->start_char = start;
1928 				cur->row_xpos = 0;
1929 			}
1930 			_formi_set_cursor_xpos(cur, FALSE);
1931 	} else {
1932 			  /* multiline field */
1933 			row = find_cur_line(cur, start);
1934 			cur->row_xpos = start - cur->lines[row].start;
1935 			cur->cursor_xpos = _formi_tab_expanded_length(
1936 				&str[cur->lines[row].start],
1937 				0, cur->row_xpos) - 1;
1938 			if (row != (cur->start_line + cur->cursor_ypos)) {
1939 				if (cur->cursor_ypos == (cur->rows - 1)) {
1940 					cur->start_line = row - cur->rows + 1;
1941 				} else {
1942 					cur->cursor_ypos = row
1943 						- cur->start_line;
1944 				}
1945 			}
1946 		}
1947 		break;
1948 
1949 	case REQ_PREV_WORD:
1950 		start = cur->start_char + cur->row_xpos
1951 			+ cur->lines[cur->start_line + cur->cursor_ypos].start;
1952 		if (cur->start_char > 0)
1953 			start--;
1954 
1955 		if (start == 0)
1956 			return E_REQUEST_DENIED;
1957 
1958 		str = cur->buffers[0].string;
1959 
1960 		start = find_sow(str, start);
1961 
1962 		if ((cur->rows + cur->nrows) == 1) {
1963 			  /* single line field */
1964 			size = _formi_tab_expanded_length(str,
1965 				cur->start_char, start);
1966 
1967 			if (start > cur->start_char) {
1968 				cur->row_xpos = start - cur->start_char;
1969 			} else {
1970 				cur->start_char = start;
1971 				cur->row_xpos = 0;
1972 			}
1973 			_formi_set_cursor_xpos(cur, FALSE);
1974 		} else {
1975 			  /* multiline field */
1976 			row = find_cur_line(cur, start);
1977 			cur->row_xpos = start - cur->lines[row].start;
1978 			cur->cursor_xpos = _formi_tab_expanded_length(
1979 				&str[cur->lines[row].start], 0,
1980 				cur->row_xpos) - 1;
1981 			if (row != (cur->start_line + cur->cursor_ypos)) {
1982 				if (cur->cursor_ypos == 0) {
1983 					cur->start_line = row;
1984 				} else {
1985 					if (cur->start_line > row) {
1986 						cur->start_line = row;
1987 						cur->cursor_ypos = 0;
1988 					} else {
1989 						cur->cursor_ypos = row -
1990 							cur->start_line;
1991 					}
1992 				}
1993 			}
1994 		}
1995 
1996 		break;
1997 
1998 	case REQ_BEG_FIELD:
1999 		cur->start_char = 0;
2000 		cur->start_line = 0;
2001 		cur->row_xpos = 0;
2002 		_formi_init_field_xpos(cur);
2003 		cur->cursor_ypos = 0;
2004 		break;
2005 
2006 	case REQ_BEG_LINE:
2007 		cur->row_xpos = 0;
2008 		_formi_init_field_xpos(cur);
2009 		cur->start_char = 0;
2010 		break;
2011 
2012 	case REQ_END_FIELD:
2013 		if (cur->row_count > cur->rows) {
2014 			cur->start_line = cur->row_count - cur->rows;
2015 			cur->cursor_ypos = cur->rows - 1;
2016 		} else {
2017 			cur->start_line = 0;
2018 			cur->cursor_ypos = cur->row_count - 1;
2019 		}
2020 
2021 		  /* we fall through here deliberately, we are on the
2022 		   * correct row, now we need to get to the end of the
2023 		   * line.
2024 		   */
2025 		  /* FALLTHRU */
2026 
2027 	case REQ_END_LINE:
2028 		row = cur->start_line + cur->cursor_ypos;
2029 		start = cur->lines[row].start;
2030 		end = cur->lines[row].end;
2031 
2032 		if ((cur->rows + cur->nrows) == 1) {
2033 			if (cur->lines[row].length > cur->cols - 1) {
2034 				if ((cur->opts & O_STATIC) != O_STATIC) {
2035 					cur->start_char = tab_fit_window(
2036 						cur, end, cur->cols) + 1;
2037 					cur->row_xpos = cur->buffers[0].length
2038 						- cur->start_char;
2039 				} else {
2040 					cur->start_char = 0;
2041 					cur->row_xpos = cur->cols - 1;
2042 				}
2043 			} else {
2044 				cur->row_xpos = end + 1;
2045 				cur->start_char = 0;
2046 			}
2047 			_formi_set_cursor_xpos(cur, FALSE);
2048 		} else {
2049 			cur->row_xpos = end - start;
2050 			cur->cursor_xpos = cur->lines[row].length - 1;
2051 			if (row == (cur->row_count - 1)) {
2052 				cur->row_xpos++;
2053 				cur->cursor_xpos++;
2054 			}
2055 		}
2056 		break;
2057 
2058 	case REQ_NEW_LINE:
2059 		if ((status = split_line(cur,
2060 				cur->start_char + cur->row_xpos)) != E_OK)
2061 			return status;
2062 		break;
2063 
2064 	case REQ_INS_CHAR:
2065 		if ((status = _formi_add_char(cur, cur->start_char
2066 					      + cur->row_xpos,
2067 					      cur->pad)) != E_OK)
2068 			return status;
2069 		break;
2070 
2071 	case REQ_INS_LINE:
2072 		start = cur->lines[cur->start_line + cur->cursor_ypos].start;
2073 		if ((status = split_line(cur, start)) != E_OK)
2074 			return status;
2075 		break;
2076 
2077 	case REQ_DEL_CHAR:
2078 		if (cur->buffers[0].length == 0)
2079 			return E_REQUEST_DENIED;
2080 
2081 		row = cur->start_line + cur->cursor_ypos;
2082 		start = cur->start_char + cur->row_xpos
2083 			+ cur->lines[row].start;
2084 		end = cur->buffers[0].length;
2085 		if (start >= cur->buffers[0].length)
2086 			return E_REQUEST_DENIED;
2087 
2088 		if (start == cur->lines[row].end) {
2089 			if ((cur->rows + cur->nrows) > 1) {
2090 				/*
2091 				 * If we have more than one row, join the
2092 				 * next row to make things easier unless
2093 				 * we are at the end of the string, in
2094 				 * that case the join would fail but we
2095 				 * really want to delete the last char
2096 				 * in the field.
2097 				 */
2098 				if ((cur->row_count > 1)
2099 				    && (start != (end - 1))) {
2100 					if (_formi_join_line(cur,
2101 							     start,
2102 							     JOIN_NEXT_NW)
2103 					    != E_OK) {
2104 						return E_REQUEST_DENIED;
2105 					}
2106 				}
2107 			}
2108 		}
2109 
2110 		saved = cur->buffers[0].string[start];
2111 		bcopy(&cur->buffers[0].string[start + 1],
2112 		      &cur->buffers[0].string[start],
2113 		      (unsigned) end - start + 1);
2114 		bump_lines(cur, _FORMI_USE_CURRENT, -1, TRUE);
2115 		cur->buffers[0].length--;
2116 
2117 		  /*
2118 		   * recalculate tabs for a single line field, multiline
2119 		   * fields will do this when the field is wrapped.
2120 		   */
2121 		if ((cur->rows + cur->nrows) == 1)
2122 			_formi_calculate_tabs(cur, 0);
2123 		  /*
2124 		   * if we are at the end of the string then back the
2125 		   * cursor pos up one to stick on the end of the line
2126 		   */
2127 		if (start == cur->buffers[0].length) {
2128 			if (cur->buffers[0].length > 1) {
2129 				if ((cur->rows + cur->nrows) == 1) {
2130 					pos = cur->row_xpos + cur->start_char;
2131 					cur->start_char =
2132 						tab_fit_window(
2133 							cur,
2134 							cur->start_char + cur->row_xpos,
2135 							cur->cols);
2136 					cur->row_xpos = pos - cur->start_char
2137 						- 1;
2138 					_formi_set_cursor_xpos(cur, FALSE);
2139 				} else {
2140 					if (cur->row_xpos == 0) {
2141 						if (cur->lines[row].start !=
2142 						    cur->buffers[0].length) {
2143 							if (_formi_join_line(
2144 								cur,
2145 								cur->lines[row].start,
2146 								JOIN_PREV_NW)
2147 							    != E_OK) {
2148 								return E_REQUEST_DENIED;
2149 							}
2150 						} else {
2151 							if (cur->row_count > 1)
2152 								cur->row_count--;
2153 						}
2154 
2155 						row = cur->start_line
2156 							+ cur->cursor_ypos;
2157 						if (row > 0)
2158 							row--;
2159 					}
2160 
2161 					cur->row_xpos = start
2162 						- cur->lines[row].start - 1;
2163 					cur->cursor_xpos =
2164 						_formi_tab_expanded_length(
2165 							&cur->buffers[0].string[cur->lines[row].start],
2166 							0, cur->row_xpos);
2167 					if ((cur->cursor_xpos > 0)
2168 					    && (start != (cur->buffers[0].length - 1)))
2169 						cur->cursor_xpos--;
2170 					if (row >= cur->rows)
2171 						cur->start_line = row
2172 							- cur->cursor_ypos;
2173 					else {
2174 						cur->start_line = 0;
2175 						cur->cursor_ypos = row;
2176 					}
2177 				}
2178 
2179 				start--;
2180 			} else {
2181 				start = 0;
2182 				cur->row_xpos = 0;
2183 				_formi_init_field_xpos(cur);
2184 			}
2185 		}
2186 
2187 		if ((cur->rows + cur->nrows) > 1) {
2188 			if (_formi_wrap_field(cur, start) != E_OK) {
2189 				bcopy(&cur->buffers[0].string[start],
2190 				      &cur->buffers[0].string[start + 1],
2191 				      (unsigned) end - start);
2192 				cur->buffers[0].length++;
2193 				cur->buffers[0].string[start] = saved;
2194 				bump_lines(cur, _FORMI_USE_CURRENT, 1, TRUE);
2195 				_formi_wrap_field(cur, start);
2196 				return E_REQUEST_DENIED;
2197 			}
2198 		}
2199 		break;
2200 
2201 	case REQ_DEL_PREV:
2202 		if ((cur->cursor_xpos == 0) && (cur->start_char == 0)
2203 		    && (cur->start_line == 0) && (cur->cursor_ypos == 0))
2204 			   return E_REQUEST_DENIED;
2205 
2206 		row = cur->start_line + cur->cursor_ypos;
2207 		start = cur->row_xpos + cur->start_char
2208 			+ cur->lines[row].start;
2209 		end = cur->buffers[0].length;
2210 
2211 		if ((cur->start_char + cur->row_xpos) == 0) {
2212 			  /*
2213 			   * Join this line to the next one, but only if
2214 			   * we are not at the end of the string because
2215 			   * in that case there are no characters to join.
2216 			   */
2217 			if (cur->lines[row].start != end) {
2218 				if (_formi_join_line(cur,
2219 						     cur->lines[row].start,
2220 						     JOIN_PREV_NW) != E_OK) {
2221 					return E_REQUEST_DENIED;
2222 				}
2223 			} else {
2224 				/* but we do want the row count decremented */
2225 				if (cur->row_count > 1)
2226 					cur->row_count--;
2227 			}
2228 		}
2229 
2230 		saved = cur->buffers[0].string[start - 1];
2231 		bcopy(&cur->buffers[0].string[start],
2232 		      &cur->buffers[0].string[start - 1],
2233 		      (unsigned) end - start + 1);
2234 		bump_lines(cur, (int) start - 1, -1, TRUE);
2235 		cur->buffers[0].length--;
2236 
2237 		if ((cur->rows + cur->nrows) == 1) {
2238 			_formi_calculate_tabs(cur, 0);
2239 			pos = cur->row_xpos + cur->start_char;
2240 			if (pos > 0)
2241 				pos--;
2242 			cur->start_char =
2243 				tab_fit_window(cur,
2244 					       cur->start_char + cur->row_xpos,
2245 					       cur->cols);
2246 			cur->row_xpos = pos - cur->start_char;
2247 			_formi_set_cursor_xpos(cur, FALSE);
2248 		} else {
2249 			pos = start - 1;
2250 			if (pos >= cur->buffers[0].length)
2251 				pos = cur->buffers[0].length - 1;
2252 
2253 			if ((_formi_wrap_field(cur, pos) != E_OK)) {
2254 				bcopy(&cur->buffers[0].string[start - 1],
2255 				      &cur->buffers[0].string[start],
2256 				      (unsigned) end - start);
2257 				cur->buffers[0].length++;
2258 				cur->buffers[0].string[start - 1] = saved;
2259 				bump_lines(cur, (int) start - 1, 1, TRUE);
2260 				_formi_wrap_field(cur, pos);
2261 				return E_REQUEST_DENIED;
2262 			}
2263 
2264 			row = find_cur_line(cur, pos);
2265 			cur->row_xpos = start - cur->lines[row].start - 1;
2266 			cur->cursor_xpos = _formi_tab_expanded_length(
2267 				&cur->buffers[0].string[cur->lines[row].start],
2268 				0, cur->row_xpos);
2269 			if ((cur->cursor_xpos > 0)
2270 			    && (pos != (cur->buffers[0].length - 1)))
2271 				cur->cursor_xpos--;
2272 
2273 			if (row >= cur->rows)
2274 				cur->start_line = row - cur->cursor_ypos;
2275 			else {
2276 				cur->start_line = 0;
2277 				cur->cursor_ypos = row;
2278 			}
2279 		}
2280 		break;
2281 
2282 	case REQ_DEL_LINE:
2283 		row = cur->start_line + cur->cursor_ypos;
2284 		start = cur->lines[row].start;
2285 		end = cur->lines[row].end;
2286 		bcopy(&cur->buffers[0].string[end + 1],
2287 		      &cur->buffers[0].string[start],
2288 		      (unsigned) cur->buffers[0].length - end + 1);
2289 
2290 		if (((cur->rows + cur->nrows) == 1) ||
2291 		    (cur->row_count == 1)) {
2292 			  /* single line case */
2293 			cur->buffers[0].length = 0;
2294 			cur->lines[0].end = cur->lines[0].length = 0;
2295 			cur->row_xpos = 0;
2296 			_formi_init_field_xpos(cur);
2297 			cur->cursor_ypos = 0;
2298 		} else {
2299 			  /* multiline field */
2300 			old_count = cur->row_count;
2301 			cur->row_count--;
2302 			if (cur->row_count == 0)
2303 				cur->row_count = 1;
2304 
2305 			if (cur->row_count > 1)
2306 				bcopy(&cur->lines[row + 1],
2307 				      &cur->lines[row],
2308 				      (unsigned) (cur->row_count - row)
2309 				      * sizeof(struct _formi_field_lines));
2310 
2311 			cur->lines[row].start = start;
2312 			len = start - end - 1; /* yes, this is negative */
2313 
2314 			if (row < (cur->row_count - 1))
2315 				bump_lines(cur, (int) start, len, FALSE);
2316 			else if (old_count == 1) {
2317 				cur->lines[0].end = cur->lines[0].length = 0;
2318 				cur->cursor_xpos = 0;
2319 				cur->row_xpos = 0;
2320 				cur->cursor_ypos = 0;
2321 			} else if (cur->row_count == 1) {
2322 				cur->lines[0].length = cur->buffers[0].length
2323 					+ len;
2324 				cur->lines[0].end = cur->lines[0].length - 1;
2325 			}
2326 
2327 			cur->buffers[0].length += len;
2328 
2329 			if (row > (cur->row_count - 1)) {
2330 				row--;
2331 				if (cur->cursor_ypos == 0) {
2332 					if (cur->start_line > 0) {
2333 						cur->start_line--;
2334 					}
2335 				} else {
2336 					cur->cursor_ypos--;
2337 				}
2338 			}
2339 
2340 			if (old_count > 1) {
2341 				if (cur->cursor_xpos > cur->lines[row].length) {
2342 					cur->cursor_xpos =
2343 						cur->lines[row].length - 1;
2344 					cur->row_xpos = cur->lines[row].end;
2345 				}
2346 
2347 				if (row >= cur->rows)
2348 					cur->start_line = row
2349 						- cur->cursor_ypos;
2350 				else {
2351 					cur->start_line = 0;
2352 					cur->cursor_ypos = row;
2353 				}
2354 			}
2355 		}
2356 		break;
2357 
2358 	case REQ_DEL_WORD:
2359 		start = cur->start_char + cur->row_xpos
2360 			+ cur->lines[row].start;
2361 		str = cur->buffers[0].string;
2362 
2363 		end = find_eow(str, start);
2364 
2365 		  /*
2366 		   * If not at the start of a word then find the start,
2367 		   * we cannot blindly call find_sow because this will
2368 		   * skip back a word if we are already at the start of
2369 		   * a word.
2370 		   */
2371 		if ((start > 0)
2372 		    && !(isblank(str[start - 1]) && !isblank(str[start])))
2373 			start = find_sow(cur->buffers[0].string, start);
2374 		bcopy(&cur->buffers[0].string[end],
2375 		      &cur->buffers[0].string[start],
2376 		      (unsigned) cur->buffers[0].length - end + 1);
2377 		len = end - start;
2378 		cur->buffers[0].length -= len;
2379 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2380 
2381 		if ((cur->rows + cur->nrows) > 1) {
2382 			row = cur->start_line + cur->cursor_ypos;
2383 			if ((row + 1) < cur->row_count) {
2384 				/*
2385 				 * if not on the last row we need to
2386 				 * join on the next row so the line
2387 				 * will be re-wrapped.
2388 				 */
2389 				_formi_join_line(cur, cur->lines[row].end,
2390 						 JOIN_NEXT_NW);
2391 			}
2392 			_formi_wrap_field(cur, start);
2393 			row = find_cur_line(cur, start);
2394 			cur->row_xpos = start - cur->lines[row].start;
2395 			cur->cursor_xpos = _formi_tab_expanded_length(
2396 				&cur->buffers[0].string[cur->lines[row].start],
2397 				0, cur->row_xpos);
2398 			if ((cur->cursor_xpos > 0)
2399 			    && (start != (cur->buffers[0].length - 1)))
2400 				cur->cursor_xpos--;
2401 		} else {
2402 			_formi_calculate_tabs(cur, 0);
2403 			cur->row_xpos = start - cur->start_char;
2404 			if (cur->row_xpos > 0)
2405 				cur->row_xpos--;
2406 			_formi_set_cursor_xpos(cur, FALSE);
2407 		}
2408 		break;
2409 
2410 	case REQ_CLR_EOL:
2411 		row = cur->start_line + cur->cursor_ypos;
2412 		start = cur->start_char + cur->cursor_xpos;
2413 		end = cur->lines[row].end;
2414 		len = end - start;
2415 		bcopy(&cur->buffers[0].string[end + 1],
2416 		      &cur->buffers[0].string[start],
2417 		      cur->buffers[0].length - end + 1);
2418 		cur->buffers[0].length -= len;
2419 		bump_lines(cur, _FORMI_USE_CURRENT, - (int) len, TRUE);
2420 
2421 		if (cur->row_xpos > cur->lines[row].length) {
2422 			cur->row_xpos = cur->lines[row].end;
2423 			if (cur->rows + cur->nrows == 1)
2424 				_formi_set_cursor_xpos(cur, FALSE);
2425 			else
2426 				cur->cursor_xpos = cur->lines[row].length;
2427 		}
2428 		break;
2429 
2430 	case REQ_CLR_EOF:
2431 		row = cur->start_line + cur->cursor_ypos;
2432 		cur->buffers[0].string[cur->start_char
2433 				      + cur->cursor_xpos] = '\0';
2434 		cur->buffers[0].length = strlen(cur->buffers[0].string);
2435 		cur->lines[row].end = cur->buffers[0].length;
2436 		cur->lines[row].length = cur->lines[row].end
2437 			- cur->lines[row].start;
2438 		break;
2439 
2440 	case REQ_CLR_FIELD:
2441 		cur->buffers[0].string[0] = '\0';
2442 		cur->buffers[0].length = 0;
2443 		cur->row_count = 1;
2444 		cur->start_line = 0;
2445 		cur->cursor_ypos = 0;
2446 		cur->row_xpos = 0;
2447 		_formi_init_field_xpos(cur);
2448 		cur->start_char = 0;
2449 		cur->lines[0].start = 0;
2450 		cur->lines[0].end = 0;
2451 		cur->lines[0].length = 0;
2452 		break;
2453 
2454 	case REQ_OVL_MODE:
2455 		cur->overlay = 1;
2456 		break;
2457 
2458 	case REQ_INS_MODE:
2459 		cur->overlay = 0;
2460 		break;
2461 
2462 	case REQ_SCR_FLINE:
2463 		_formi_scroll_fwd(cur, 1);
2464 		break;
2465 
2466 	case REQ_SCR_BLINE:
2467 		_formi_scroll_back(cur, 1);
2468 		break;
2469 
2470 	case REQ_SCR_FPAGE:
2471 		_formi_scroll_fwd(cur, cur->rows);
2472 		break;
2473 
2474 	case REQ_SCR_BPAGE:
2475 		_formi_scroll_back(cur, cur->rows);
2476 		break;
2477 
2478 	case REQ_SCR_FHPAGE:
2479 		_formi_scroll_fwd(cur, cur->rows / 2);
2480 		break;
2481 
2482 	case REQ_SCR_BHPAGE:
2483 		_formi_scroll_back(cur, cur->rows / 2);
2484 		break;
2485 
2486 	case REQ_SCR_FCHAR:
2487 		_formi_hscroll_fwd(cur, 1);
2488 		break;
2489 
2490 	case REQ_SCR_BCHAR:
2491 		_formi_hscroll_back(cur, 1);
2492 		break;
2493 
2494 	case REQ_SCR_HFLINE:
2495 		_formi_hscroll_fwd(cur, cur->cols);
2496 		break;
2497 
2498 	case REQ_SCR_HBLINE:
2499 		_formi_hscroll_back(cur, cur->cols);
2500 		break;
2501 
2502 	case REQ_SCR_HFHALF:
2503 		_formi_hscroll_fwd(cur, cur->cols / 2);
2504 		break;
2505 
2506 	case REQ_SCR_HBHALF:
2507 		_formi_hscroll_back(cur, cur->cols / 2);
2508 		break;
2509 
2510 	default:
2511 		return 0;
2512 	}
2513 
2514 #ifdef DEBUG
2515 	fprintf(dbg,
2516 	 "exit: xpos=%d, row_pos=%d, start_char=%d, length=%d, allocated=%d\n",
2517 		cur->cursor_xpos, cur->row_xpos, cur->start_char,
2518 		cur->buffers[0].length,	cur->buffers[0].allocated);
2519 	fprintf(dbg, "exit: start_line=%d, ypos=%d\n", cur->start_line,
2520 		cur->cursor_ypos);
2521 	fprintf(dbg, "exit: string=\"%s\"\n", cur->buffers[0].string);
2522 	assert ((cur->cursor_xpos < INT_MAX) && (cur->row_xpos < INT_MAX)
2523 		&& (cur->cursor_xpos >= cur->row_xpos));
2524 #endif
2525 	return 1;
2526 }
2527 
2528 /*
2529  * Validate the give character by passing it to any type character
2530  * checking routines, if they exist.
2531  */
2532 int
2533 _formi_validate_char(FIELD *field, char c)
2534 {
2535 	int ret_val;
2536 
2537 	if (field->type == NULL)
2538 		return E_OK;
2539 
2540 	ret_val = E_INVALID_FIELD;
2541 	_formi_do_char_validation(field, field->type, c, &ret_val);
2542 
2543 	return ret_val;
2544 }
2545 
2546 
2547 /*
2548  * Perform the validation of the character, invoke all field_type validation
2549  * routines.  If the field is ok then update ret_val to E_OK otherwise
2550  * ret_val is not changed.
2551  */
2552 static void
2553 _formi_do_char_validation(FIELD *field, FIELDTYPE *type, char c, int *ret_val)
2554 {
2555 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2556 		_formi_do_char_validation(field, type->link->next, c, ret_val);
2557 		_formi_do_char_validation(field, type->link->prev, c, ret_val);
2558 	} else {
2559 		if (type->char_check == NULL)
2560 			*ret_val = E_OK;
2561 		else {
2562 			if (type->char_check((int)(unsigned char) c,
2563 					     field->args) == TRUE)
2564 				*ret_val = E_OK;
2565 		}
2566 	}
2567 }
2568 
2569 /*
2570  * Validate the current field.  If the field validation returns success then
2571  * return E_OK otherwise return E_INVALID_FIELD.
2572  *
2573  */
2574 int
2575 _formi_validate_field(FORM *form)
2576 {
2577 	FIELD *cur;
2578 	char *bp;
2579 	int ret_val, count;
2580 
2581 
2582 	if ((form == NULL) || (form->fields == NULL) ||
2583 	    (form->fields[0] == NULL))
2584 		return E_INVALID_FIELD;
2585 
2586 	cur = form->fields[form->cur_field];
2587 
2588 	bp = cur->buffers[0].string;
2589 	count = _formi_skip_blanks(bp, 0);
2590 
2591 	  /* check if we have a null field, depending on the nullok flag
2592 	   * this may be acceptable or not....
2593 	   */
2594 	if (cur->buffers[0].string[count] == '\0') {
2595 		if ((cur->opts & O_NULLOK) == O_NULLOK)
2596 			return E_OK;
2597 		else
2598 			return E_INVALID_FIELD;
2599 	}
2600 
2601 	  /* check if an unmodified field is ok */
2602 	if (cur->buf0_status == 0) {
2603 		if ((cur->opts & O_PASSOK) == O_PASSOK)
2604 			return E_OK;
2605 		else
2606 			return E_INVALID_FIELD;
2607 	}
2608 
2609 	  /* if there is no type then just accept the field */
2610 	if (cur->type == NULL)
2611 		return E_OK;
2612 
2613 	ret_val = E_INVALID_FIELD;
2614 	_formi_do_validation(cur, cur->type, &ret_val);
2615 
2616 	return ret_val;
2617 }
2618 
2619 /*
2620  * Perform the validation of the field, invoke all field_type validation
2621  * routines.  If the field is ok then update ret_val to E_OK otherwise
2622  * ret_val is not changed.
2623  */
2624 static void
2625 _formi_do_validation(FIELD *field, FIELDTYPE *type, int *ret_val)
2626 {
2627 	if ((type->flags & _TYPE_IS_LINKED) == _TYPE_IS_LINKED) {
2628 		_formi_do_validation(field, type->link->next, ret_val);
2629 		_formi_do_validation(field, type->link->prev, ret_val);
2630 	} else {
2631 		if (type->field_check == NULL)
2632 			*ret_val = E_OK;
2633 		else {
2634 			if (type->field_check(field, field_buffer(field, 0))
2635 			    == TRUE)
2636 				*ret_val = E_OK;
2637 		}
2638 	}
2639 }
2640 
2641 /*
2642  * Select the next/previous choice for the field, the driver command
2643  * selecting the direction will be passed in c.  Return 1 if a choice
2644  * selection succeeded, 0 otherwise.
2645  */
2646 int
2647 _formi_field_choice(FORM *form, int c)
2648 {
2649 	FIELDTYPE *type;
2650 	FIELD *field;
2651 
2652 	if ((form == NULL) || (form->fields == NULL) ||
2653 	    (form->fields[0] == NULL) ||
2654 	    (form->fields[form->cur_field]->type == NULL))
2655 		return 0;
2656 
2657 	field = form->fields[form->cur_field];
2658 	type = field->type;
2659 
2660 	switch (c) {
2661 	case REQ_NEXT_CHOICE:
2662 		if (type->next_choice == NULL)
2663 			return 0;
2664 		else
2665 			return type->next_choice(field,
2666 						 field_buffer(field, 0));
2667 
2668 	case REQ_PREV_CHOICE:
2669 		if (type->prev_choice == NULL)
2670 			return 0;
2671 		else
2672 			return type->prev_choice(field,
2673 						 field_buffer(field, 0));
2674 
2675 	default: /* should never happen! */
2676 		return 0;
2677 	}
2678 }
2679 
2680 /*
2681  * Update the fields if they have changed.  The parameter old has the
2682  * previous current field as the current field may have been updated by
2683  * the driver.  Return 1 if the form page needs updating.
2684  *
2685  */
2686 int
2687 _formi_update_field(FORM *form, int old_field)
2688 {
2689 	int cur, i;
2690 
2691 	cur = form->cur_field;
2692 
2693 	if (old_field != cur) {
2694 		if (!((cur >= form->page_starts[form->page].first) &&
2695 		      (cur <= form->page_starts[form->page].last))) {
2696 			  /* not on same page any more */
2697 			for (i = 0; i < form->max_page; i++) {
2698 				if ((form->page_starts[i].in_use == 1) &&
2699 				    (form->page_starts[i].first <= cur) &&
2700 				    (form->page_starts[i].last >= cur)) {
2701 					form->page = i;
2702 					return 1;
2703 				}
2704 			}
2705 		}
2706 	}
2707 
2708 	_formi_redraw_field(form, old_field);
2709 	_formi_redraw_field(form, form->cur_field);
2710 	return 0;
2711 }
2712 
2713 /*
2714  * Compare function for the field sorting
2715  *
2716  */
2717 static int
2718 field_sort_compare(const void *one, const void *two)
2719 {
2720 	const FIELD *a, *b;
2721 	int tl;
2722 
2723 	  /* LINTED const castaway; we don't modify these! */
2724 	a = (const FIELD *) *((const FIELD **) one);
2725 	b = (const FIELD *) *((const FIELD **) two);
2726 
2727 	if (a == NULL)
2728 		return 1;
2729 
2730 	if (b == NULL)
2731 		return -1;
2732 
2733 	  /*
2734 	   * First check the page, we want the fields sorted by page.
2735 	   *
2736 	   */
2737 	if (a->page != b->page)
2738 		return ((a->page > b->page)? 1 : -1);
2739 
2740 	tl = _formi_top_left(a->parent, a->index, b->index);
2741 
2742 	  /*
2743 	   * sort fields left to right, top to bottom so the top left is
2744 	   * the less than value....
2745 	   */
2746 	return ((tl == a->index)? -1 : 1);
2747 }
2748 
2749 /*
2750  * Sort the fields in a form ready for driver traversal.
2751  */
2752 void
2753 _formi_sort_fields(FORM *form)
2754 {
2755 	FIELD **sort_area;
2756 	int i;
2757 
2758 	CIRCLEQ_INIT(&form->sorted_fields);
2759 
2760 	if ((sort_area = (FIELD **) malloc(sizeof(FIELD *) * form->field_count))
2761 	    == NULL)
2762 		return;
2763 
2764 	bcopy(form->fields, sort_area, sizeof(FIELD *) * form->field_count);
2765 	qsort(sort_area, (unsigned) form->field_count, sizeof(FIELD *),
2766 	      field_sort_compare);
2767 
2768 	for (i = 0; i < form->field_count; i++)
2769 		CIRCLEQ_INSERT_TAIL(&form->sorted_fields, sort_area[i], glue);
2770 
2771 	free(sort_area);
2772 }
2773 
2774 /*
2775  * Set the neighbours for all the fields in the given form.
2776  */
2777 void
2778 _formi_stitch_fields(FORM *form)
2779 {
2780 	int above_row, below_row, end_above, end_below, cur_row, real_end;
2781 	FIELD *cur, *above, *below;
2782 
2783 	  /*
2784 	   * check if the sorted fields circle queue is empty, just
2785 	   * return if it is.
2786 	   */
2787 	if (CIRCLEQ_EMPTY(&form->sorted_fields))
2788 		return;
2789 
2790 	  /* initially nothing is above..... */
2791 	above_row = -1;
2792 	end_above = TRUE;
2793 	above = NULL;
2794 
2795 	  /* set up the first field as the current... */
2796 	cur = CIRCLEQ_FIRST(&form->sorted_fields);
2797 	cur_row = cur->form_row;
2798 
2799 	  /* find the first field on the next row if any */
2800 	below = CIRCLEQ_NEXT(cur, glue);
2801 	below_row = -1;
2802 	end_below = TRUE;
2803 	real_end = TRUE;
2804 	while (below != (void *)&form->sorted_fields) {
2805 		if (below->form_row != cur_row) {
2806 			below_row = below->form_row;
2807 			end_below = FALSE;
2808 			real_end = FALSE;
2809 			break;
2810 		}
2811 		below = CIRCLEQ_NEXT(below, glue);
2812 	}
2813 
2814 	  /* walk the sorted fields, setting the neighbour pointers */
2815 	while (cur != (void *) &form->sorted_fields) {
2816 		if (cur == CIRCLEQ_FIRST(&form->sorted_fields))
2817 			cur->left = NULL;
2818 		else
2819 			cur->left = CIRCLEQ_PREV(cur, glue);
2820 
2821 		if (cur == CIRCLEQ_LAST(&form->sorted_fields))
2822 			cur->right = NULL;
2823 		else
2824 			cur->right = CIRCLEQ_NEXT(cur, glue);
2825 
2826 		if (end_above == TRUE)
2827 			cur->up = NULL;
2828 		else {
2829 			cur->up = above;
2830 			above = CIRCLEQ_NEXT(above, glue);
2831 			if (above_row != above->form_row) {
2832 				end_above = TRUE;
2833 				above_row = above->form_row;
2834 			}
2835 		}
2836 
2837 		if (end_below == TRUE)
2838 			cur->down = NULL;
2839 		else {
2840 			cur->down = below;
2841 			below = CIRCLEQ_NEXT(below, glue);
2842 			if (below == (void *) &form->sorted_fields) {
2843 				end_below = TRUE;
2844 				real_end = TRUE;
2845 			} else if (below_row != below->form_row) {
2846 				end_below = TRUE;
2847 				below_row = below->form_row;
2848 			}
2849 		}
2850 
2851 		cur = CIRCLEQ_NEXT(cur, glue);
2852 		if ((cur != (void *) &form->sorted_fields)
2853 		    && (cur_row != cur->form_row)) {
2854 			cur_row = cur->form_row;
2855 			if (end_above == FALSE) {
2856 				for (; above != CIRCLEQ_FIRST(&form->sorted_fields);
2857 				     above = CIRCLEQ_NEXT(above, glue)) {
2858 					if (above->form_row != above_row) {
2859 						above_row = above->form_row;
2860 						break;
2861 					}
2862 				}
2863 			} else if (above == NULL) {
2864 				above = CIRCLEQ_FIRST(&form->sorted_fields);
2865 				end_above = FALSE;
2866 				above_row = above->form_row;
2867 			} else
2868 				end_above = FALSE;
2869 
2870 			if (end_below == FALSE) {
2871 				while (below_row == below->form_row) {
2872 					below = CIRCLEQ_NEXT(below,
2873 							     glue);
2874 					if (below ==
2875 					    (void *)&form->sorted_fields) {
2876 						real_end = TRUE;
2877 						end_below = TRUE;
2878 						break;
2879 					}
2880 				}
2881 
2882 				if (below != (void *)&form->sorted_fields)
2883 					below_row = below->form_row;
2884 			} else if (real_end == FALSE)
2885 				end_below = FALSE;
2886 
2887 		}
2888 	}
2889 }
2890 
2891 /*
2892  * Calculate the length of the displayed line allowing for any tab
2893  * characters that need to be expanded.  We assume that the tab stops
2894  * are 8 characters apart.  The parameters start and end are the
2895  * character positions in the string str we want to get the length of,
2896  * the function returns the number of characters from the start
2897  * position to the end position that should be displayed after any
2898  * intervening tabs have been expanded.
2899  */
2900 int
2901 _formi_tab_expanded_length(char *str, unsigned int start, unsigned int end)
2902 {
2903 	int len, start_len, i;
2904 
2905 	  /* if we have a null string then there is no length */
2906 	if (str[0] == '\0')
2907 		return 0;
2908 
2909 	len = 0;
2910 	start_len = 0;
2911 
2912 	  /*
2913 	   * preceding tabs affect the length tabs in the span, so
2914 	   * we need to calculate the length including the stuff before
2915 	   * start and then subtract off the unwanted bit.
2916 	   */
2917 	for (i = 0; i <= end; i++) {
2918 		if (i == start) /* stash preamble length for later */
2919 			start_len = len;
2920 
2921 		if (str[i] == '\0')
2922 			break;
2923 
2924 		if (str[i] == '\t')
2925 			len = len - (len % 8) + 8;
2926 		else
2927 			len++;
2928 	}
2929 
2930 #ifdef DEBUG
2931 	if (dbg != NULL) {
2932 		fprintf(dbg,
2933 		    "tab_expanded: start=%d, end=%d, expanded=%d (diff=%d)\n",
2934 			start, end, (len - start_len), (end - start));
2935 	}
2936 #endif
2937 
2938 	return (len - start_len);
2939 }
2940 
2941 /*
2942  * Calculate the tab stops on a given line in the field and set up
2943  * the tabs list with the results.  We do this by scanning the line for tab
2944  * characters and if one is found, noting the position and the number of
2945  * characters to get to the next tab stop.  This information is kept to
2946  * make manipulating the field (scrolling and so on) easier to handle.
2947  */
2948 void
2949 _formi_calculate_tabs(FIELD *field, unsigned row)
2950 {
2951 	_formi_tab_t *ts = field->lines[row].tabs, *old_ts = NULL, **tsp;
2952 	int i, j;
2953 
2954 	  /*
2955 	   * If the line already has tabs then invalidate them by
2956 	   * walking the list and killing the in_use flag.
2957 	   */
2958 	for (; ts != NULL; ts = ts->fwd)
2959 		ts->in_use = FALSE;
2960 
2961 
2962 	  /*
2963 	   * Now look for tabs in the row and record the info...
2964 	   */
2965 	tsp = &field->lines[row].tabs;
2966 	for (i = field->lines[row].start, j = 0; i <= field->lines[row].end;
2967 	     i++, j++) {
2968 		if (field->buffers[0].string[i] == '\t') {
2969 			if (*tsp == NULL) {
2970 				if ((*tsp = (_formi_tab_t *)
2971 				     malloc(sizeof(_formi_tab_t))) == NULL)
2972 					return;
2973 				(*tsp)->back = old_ts;
2974 				(*tsp)->fwd = NULL;
2975 			}
2976 
2977 			(*tsp)->in_use = TRUE;
2978 			(*tsp)->pos = i - field->lines[row].start;
2979 			(*tsp)->size = 8 - (j % 8);
2980 			j += (*tsp)->size - 1;
2981 			old_ts = *tsp;
2982 			tsp = &(*tsp)->fwd;
2983 		}
2984 	}
2985 }
2986 
2987 /*
2988  * Return the size of the tab padding for a tab character at the given
2989  * position.  Return 1 if there is not a tab char entry matching the
2990  * given location.
2991  */
2992 static int
2993 tab_size(FIELD *field, unsigned int offset, unsigned int i)
2994 {
2995 	int row;
2996 	_formi_tab_t *ts;
2997 
2998 	row = find_cur_line(field, offset + i);
2999 	ts = field->lines[row].tabs;
3000 
3001 	while ((ts != NULL) && (ts->pos != i))
3002 		ts = ts->fwd;
3003 
3004 	if (ts == NULL)
3005 		return 1;
3006 	else
3007 		return ts->size;
3008 }
3009 
3010 /*
3011  * Find the character offset that corresponds to longest tab expanded
3012  * string that will fit into the given window.  Walk the string backwards
3013  * evaluating the sizes of any tabs that are in the string.  Note that
3014  * using this function on a multi-line window will produce undefined
3015  * results - it is really only required for a single row field.
3016  */
3017 static int
3018 tab_fit_window(FIELD *field, unsigned int pos, unsigned int window)
3019 {
3020 	int scroll_amt, i;
3021 	_formi_tab_t *ts;
3022 
3023 	  /* first find the last tab */
3024 	ts = field->lines[0].tabs;
3025 
3026 	  /*
3027 	   * unless there are no tabs - just return the window size,
3028 	   * if there is enough room, otherwise 0.
3029 	   */
3030 	if (ts == NULL) {
3031 		if (field->buffers[0].length < window)
3032 			return 0;
3033 		else
3034 			return field->buffers[0].length - window + 1;
3035 	}
3036 
3037 	while ((ts->fwd != NULL) && (ts->fwd->in_use == TRUE))
3038 		ts = ts->fwd;
3039 
3040 	  /*
3041 	   * now walk backwards finding the first tab that is to the
3042 	   * left of our starting pos.
3043 	   */
3044 	while ((ts != NULL) && (ts->in_use == TRUE) && (ts->pos > pos))
3045 		ts = ts->back;
3046 
3047 	scroll_amt = 0;
3048 	for (i = pos; i >= 0; i--) {
3049 		if (field->buffers[0].string[i] == '\t') {
3050 #ifdef DEBUG
3051 			assert((ts != NULL) && (ts->in_use == TRUE));
3052 #endif
3053 			if (ts->pos == i) {
3054 				if ((scroll_amt + ts->size) > window) {
3055 					break;
3056 				}
3057 				scroll_amt += ts->size;
3058 				ts = ts->back;
3059 			}
3060 #ifdef DEBUG
3061 			else
3062 				assert(ts->pos == i);
3063 #endif
3064 		} else {
3065 			scroll_amt++;
3066 			if (scroll_amt > window)
3067 				break;
3068 		}
3069 	}
3070 
3071 	return ++i;
3072 }
3073 
3074 /*
3075  * Return the position of the last character that will fit into the
3076  * given width after tabs have been expanded for a given row of a given
3077  * field.
3078  */
3079 static unsigned int
3080 tab_fit_len(FIELD *field, unsigned int row, unsigned int width)
3081 {
3082 	unsigned int pos, len, row_pos;
3083 	_formi_tab_t *ts;
3084 
3085 	ts = field->lines[row].tabs;
3086 	pos = field->lines[row].start;
3087 	len = 0;
3088 	row_pos = 0;
3089 
3090 	while ((len < width) && (pos < field->buffers[0].length)) {
3091 		if (field->buffers[0].string[pos] == '\t') {
3092 #ifdef DEBUG
3093 			assert((ts != NULL) && (ts->in_use == TRUE));
3094 #endif
3095 			if (ts->pos == row_pos) {
3096 				if ((len + ts->size) > width)
3097 					break;
3098 				len += ts->size;
3099 				ts = ts->fwd;
3100 			}
3101 #ifdef DEBUG
3102 			else
3103 				assert(ts->pos == row_pos);
3104 #endif
3105 		} else
3106 			len++;
3107 		pos++;
3108 		row_pos++;
3109 	}
3110 
3111 	if (pos > 0)
3112 		pos--;
3113 	return pos;
3114 }
3115