xref: /netbsd-src/lib/libform/field.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: field.c,v 1.22 2003/03/09 00:57:17 lukem Exp $	*/
2 /*-
3  * Copyright (c) 1998-1999 Brett Lymn
4  *                         (blymn@baea.com.au, brett_lymn@yahoo.com.au)
5  * All rights reserved.
6  *
7  * This code has been donated to The NetBSD Foundation by the Author.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: field.c,v 1.22 2003/03/09 00:57:17 lukem Exp $");
33 
34 #include <stdlib.h>
35 #include <strings.h>
36 #include <stdarg.h>
37 #include <form.h>
38 #include "internals.h"
39 
40 extern FORM _formi_default_form;
41 
42 FIELD _formi_default_field = {
43 	0, /* rows in the field */
44 	0, /* columns in the field */
45 	0, /* dynamic rows */
46 	0, /* dynamic columns */
47 	0, /* maximum growth */
48 	0, /* starting row in the form subwindow */
49 	0, /* starting column in the form subwindow */
50 	0, /* number of off screen rows */
51 	0, /* index of this field in form fields array. */
52 	0, /* number of buffers associated with this field */
53 	FALSE, /* set to true if buffer 0 has changed. */
54 	NO_JUSTIFICATION, /* justification style of the field */
55 	FALSE, /* set to true if field is in overlay mode */
56 	0, /* starting char in string (horiz scroll) */
57 	0, /* starting line in field (vert scroll) */
58 	0, /* number of rows actually used in field */
59 	0, /* actual pos of cursor in row, not same as x pos due to tabs */
60 	0, /* x pos of cursor in field */
61 	0, /* y pos of cursor in field */
62 	0, /* start of a new page on the form if 1 */
63 	0, /* number of the page this field is on */
64 	A_NORMAL, /* character attributes for the foreground */
65 	A_NORMAL, /* character attributes for the background */
66 	' ', /* padding character */
67 	DEFAULT_FORM_OPTS, /* options for the field */
68 	NULL, /* the form this field is bound to, if any */
69 	NULL, /* field above this one */
70 	NULL, /* field below this one */
71 	NULL, /* field to the left of this one */
72 	NULL, /* field to the right of this one */
73 	NULL,  /* user defined pointer. */
74 	NULL, /* used if fields are linked */
75 	NULL, /* type struct for the field */
76 	{NULL, NULL}, /* circle queue glue for sorting fields */
77 	NULL, /* args for field type. */
78 	0,    /* number of allocated slots in lines array */
79 	NULL, /* pointer to the array of lines structures. */
80 	NULL, /* array of buffers for the field */
81 };
82 
83 /* internal function prototypes */
84 static int
85 field_buffer_init(FIELD *field, int buffer, size_t len);
86 static FIELD *
87 _formi_create_field(FIELD *, int, int, int, int, int, int);
88 
89 
90 /*
91  * Set the userptr for the field
92  */
93 int
94 set_field_userptr(FIELD *field, void *ptr)
95 {
96 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
97 
98 	fp->userptr = ptr;
99 
100 	return E_OK;
101 }
102 
103 /*
104  * Return the userptr for the field.
105  */
106 
107 void *
108 field_userptr(FIELD *field)
109 {
110 	if (field == NULL)
111 		return _formi_default_field.userptr;
112 	else
113 		return field->userptr;
114 }
115 
116 /*
117  * Set the options for the designated field.
118  */
119 int
120 set_field_opts(FIELD *field, Form_Options options)
121 {
122 	int i;
123 
124 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
125 
126 	  /* not allowed to set opts if the field is the current one */
127 	if ((field != NULL) && (field->parent != NULL) &&
128 	    (field->parent->cur_field == field->index))
129 		return E_CURRENT;
130 
131 	if ((options & O_STATIC) == O_STATIC) {
132 		for (i = 0; i < fp->nbuf; i++) {
133 			if (fp->buffers[i].length > fp->cols)
134 				fp->buffers[i].string[fp->cols] = '\0';
135 		}
136 	}
137 
138 	fp->opts = options;
139 
140 	  /* if appropriate, redraw the field */
141 	if ((field != NULL) && (field->parent != NULL)
142 	    && (field->parent->posted == 1)) {
143 		_formi_redraw_field(field->parent, field->index);
144 		pos_form_cursor(field->parent);
145 		wrefresh(field->parent->scrwin);
146 	}
147 
148 	return E_OK;
149 }
150 
151 /*
152  * Turn on the passed field options.
153  */
154 int
155 field_opts_on(FIELD *field, Form_Options options)
156 {
157 	int i;
158 
159 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
160 
161 	  /* not allowed to set opts if the field is the current one */
162 	if ((field != NULL) && (field->parent != NULL) &&
163 	    (field->parent->cur_field == field->index))
164 		return E_CURRENT;
165 
166 	if ((options & O_STATIC) == O_STATIC) {
167 		for (i = 0; i < fp->nbuf; i++) {
168 			if (fp->buffers[i].length > fp->cols)
169 				fp->buffers[i].string[fp->cols] = '\0';
170 		}
171 	}
172 
173 	fp->opts |= options;
174 
175 	  /* if appropriate, redraw the field */
176 	if ((field != NULL) && (field->parent != NULL)
177 	    && (field->parent->posted == 1)) {
178 		_formi_redraw_field(field->parent, field->index);
179 		pos_form_cursor(field->parent);
180 		wrefresh(field->parent->scrwin);
181 	}
182 
183 	return E_OK;
184 }
185 
186 /*
187  * Turn off the passed field options.
188  */
189 int
190 field_opts_off(FIELD *field, Form_Options options)
191 {
192 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
193 
194 	  /* not allowed to set opts if the field is the current one */
195 	if ((field != NULL) && (field->parent != NULL) &&
196 	    (field->parent->cur_field == field->index))
197 		return E_CURRENT;
198 
199 	fp->opts &= ~options;
200 
201 	  /* if appropriate, redraw the field */
202 	if ((field != NULL) && (field->parent != NULL)
203 	    && (field->parent->posted == 1)) {
204 		_formi_redraw_field(field->parent, field->index);
205 		pos_form_cursor(field->parent);
206 		wrefresh(field->parent->scrwin);
207 	}
208 
209 	return E_OK;
210 }
211 
212 /*
213  * Return the field options associated with the passed field.
214  */
215 Form_Options
216 field_opts(FIELD *field)
217 {
218 	if (field == NULL)
219 		return _formi_default_field.opts;
220 	else
221 		return field->opts;
222 }
223 
224 /*
225  * Set the justification for the passed field.
226  */
227 int
228 set_field_just(FIELD *field, int justification)
229 {
230 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
231 
232 	  /*
233 	   * not allowed to set justification if the field is
234 	   * the current one
235 	   */
236 	if ((field != NULL) && (field->parent != NULL) &&
237 	    (field->parent->cur_field == field->index))
238 		return E_CURRENT;
239 
240 	if ((justification < MIN_JUST_STYLE) /* check justification valid */
241 	    || (justification > MAX_JUST_STYLE))
242 		return E_BAD_ARGUMENT;
243 
244 	  /* only allow justification on static, single row fields */
245 	if (((fp->opts & O_STATIC) != O_STATIC) ||
246 	    ((fp->rows + fp->nrows) > 1))
247 		return E_BAD_ARGUMENT;
248 
249 	fp->justification = justification;
250 
251 	_formi_init_field_xpos(fp);
252 
253 	return E_OK;
254 }
255 
256 /*
257  * Return the justification style of the field passed.
258  */
259 int
260 field_just(FIELD *field)
261 {
262 	if (field == NULL)
263 		return _formi_default_field.justification;
264 	else
265 		return field->justification;
266 }
267 
268 /*
269  * Return information about the field passed.
270  */
271 int
272 field_info(FIELD *field, int *rows, int *cols, int *frow, int *fcol,
273 	   int *nrow, int *nbuf)
274 {
275 	if (field == NULL)
276 		return E_BAD_ARGUMENT;
277 
278 	*rows = field->rows;
279 	*cols = field->cols;
280 	*frow = field->form_row;
281 	*fcol = field->form_col;
282 	*nrow = field->nrows;
283 	*nbuf = field->nbuf;
284 
285 	return E_OK;
286 }
287 
288 /*
289  * Report the dynamic field information.
290  */
291 int
292 dynamic_field_info(FIELD *field, int *drows, int *dcols, int *max)
293 {
294 	if (field == NULL)
295 		return E_BAD_ARGUMENT;
296 
297 	if ((field->opts & O_STATIC) == O_STATIC) {
298 		*drows = field->rows;
299 		*dcols = field->cols;
300 	} else {
301 		*drows = field->drows;
302 		*dcols = field->dcols;
303 	}
304 
305 	*max = field->max;
306 
307 	return E_OK;
308 }
309 
310 /*
311  * Init all the field variables, perform wrapping and other tasks
312  * after the field buffer is set.
313  */
314 static int
315 field_buffer_init(FIELD *field, int buffer, size_t len)
316 {
317 	int status;
318 
319 	if (buffer == 0) {
320 		field->start_char = 0;
321 		field->start_line = 0;
322 		field->row_xpos = 0;
323 		field->cursor_xpos = 0;
324 		field->cursor_ypos = 0;
325 		field->row_count = 1; /* must be at least one row */
326 		field->lines[0].start = 0;
327 		field->lines[0].end = (len > 0)? (len - 1) : 0;
328 		field->lines[0].length =
329 			_formi_tab_expanded_length(field->buffers[0].string,
330 						   0, field->lines[0].end);
331 
332 		  /* we have to hope the wrap works - if it does not then the
333 		     buffer is pretty much borked */
334 		status = _formi_wrap_field(field, 0);
335 		if (status != E_OK)
336 			return status;
337 
338 		  /*
339 		   * calculate the tabs for a single row field, the
340 		   * multiline case is handled when the wrap is done.
341 		   */
342 		if (field->row_count == 1)
343 			_formi_calculate_tabs(field, 0);
344 
345 		  /* redraw the field to reflect the new contents. If the field
346 		   * is attached....
347 		   */
348 		if ((field->parent != NULL) && (field->parent->posted == 1)) {
349 			_formi_redraw_field(field->parent, field->index);
350 			  /* make sure cursor goes back to current field */
351 			pos_form_cursor(field->parent);
352 		}
353 	}
354 
355 	return E_OK;
356 }
357 
358 
359 /*
360  * Set the field buffer to the string that results from processing
361  * the given format (fmt) using sprintf.
362  */
363 int
364 set_field_printf(FIELD *field, int buffer, char *fmt, ...)
365 {
366 	int len;
367 	va_list args;
368 
369 	if (field == NULL)
370 		return E_BAD_ARGUMENT;
371 
372 	if (buffer >= field->nbuf)
373 		return E_BAD_ARGUMENT;
374 
375 	va_start(args, fmt);
376 	  /* check for buffer already existing, free the storage */
377 	if (field->buffers[buffer].allocated != 0)
378 		free(field->buffers[buffer].string);
379 
380 	len = vasprintf(&field->buffers[buffer].string, fmt, args);
381 	va_end(args);
382 	if (len < 0)
383 		return E_SYSTEM_ERROR;
384 
385 	field->buffers[buffer].length = len;
386 	field->buffers[buffer].allocated = len + 1;
387 	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
388 	    && ((field->rows + field->nrows) == 1))
389 		len = field->cols;
390 
391 	field->buffers[buffer].string[len] = '\0';
392 	return field_buffer_init(field, buffer, (unsigned int) len);
393 }
394 
395 /*
396  * Set the value of the field buffer to the value given.
397  */
398 
399 int
400 set_field_buffer(FIELD *field, int buffer, char *value)
401 {
402 	size_t len;
403 	int status;
404 
405 	if (field == NULL)
406 		return E_BAD_ARGUMENT;
407 
408 	if (buffer >= field->nbuf) /* make sure buffer is valid */
409 		return E_BAD_ARGUMENT;
410 
411 	len = strlen(value);
412 	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
413 	    && ((field->rows + field->nrows) == 1))
414 		len = field->cols;
415 
416 #ifdef DEBUG
417 	if (_formi_create_dbg_file() != E_OK)
418 		return E_SYSTEM_ERROR;
419 
420 	fprintf(dbg,
421 		"set_field_buffer: entry: len = %d, value = %s, buffer=%d\n",
422 		len, value, buffer);
423 	fprintf(dbg, "set_field_buffer: entry: string = ");
424 	if (field->buffers[buffer].string != NULL)
425 		fprintf(dbg, "%s, len = %d\n", field->buffers[buffer].string,
426 			field->buffers[buffer].length);
427 	else
428 		fprintf(dbg, "(null), len = 0\n");
429 	fprintf(dbg, "set_field_buffer: entry: lines.len = %d\n",
430 		field->lines[0].length);
431 #endif
432 
433 	if ((field->buffers[buffer].string =
434 	     (char *) realloc(field->buffers[buffer].string, len + 1)) == NULL)
435 		return E_SYSTEM_ERROR;
436 
437 	strlcpy(field->buffers[buffer].string, value, len + 1);
438 	field->buffers[buffer].length = len;
439 	field->buffers[buffer].allocated = len + 1;
440 	status = field_buffer_init(field, buffer, len);
441 
442 #ifdef DEBUG
443 	fprintf(dbg, "set_field_buffer: exit: len = %d, value = %s\n",
444 		len, value);
445 	fprintf(dbg, "set_field_buffer: exit: string = %s, len = %d\n",
446 		field->buffers[buffer].string, field->buffers[buffer].length);
447 	fprintf(dbg, "set_field_buffer: exit: lines.len = %d\n",
448 		field->lines[0].length);
449 #endif
450 
451 	return status;
452 }
453 
454 /*
455  * Return the requested field buffer to the caller.
456  */
457 char *
458 field_buffer(FIELD *field, int buffer)
459 {
460 
461 	if (field == NULL)
462 		return NULL;
463 
464 	if (buffer >= field->nbuf)
465 		return NULL;
466 
467 	return field->buffers[buffer].string;
468 }
469 
470 /*
471  * Set the buffer 0 field status.
472  */
473 int
474 set_field_status(FIELD *field, int status)
475 {
476 
477 	if (field == NULL)
478 		return E_BAD_ARGUMENT;
479 
480 	if (status != FALSE)
481 		field->buf0_status = TRUE;
482 	else
483 		field->buf0_status = FALSE;
484 
485 	return E_OK;
486 }
487 
488 /*
489  * Return the buffer 0 status flag for the given field.
490  */
491 int
492 field_status(FIELD *field)
493 {
494 
495 	if (field == NULL) /* the default buffer 0 never changes :-) */
496 		return FALSE;
497 
498 	return field->buf0_status;
499 }
500 
501 /*
502  * Set the maximum growth for a dynamic field.
503  */
504 int
505 set_max_field(FIELD *fptr, int max)
506 {
507 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
508 
509 	if ((field->opts & O_STATIC) == O_STATIC) /* check if field dynamic */
510 		return E_BAD_ARGUMENT;
511 
512 	if (max < 0) /* negative numbers are bad.... */
513 		return E_BAD_ARGUMENT;
514 
515 	field->max = max;
516 	return E_OK;
517 }
518 
519 /*
520  * Set the field foreground character attributes.
521  */
522 int
523 set_field_fore(FIELD *fptr, chtype attribute)
524 {
525 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
526 
527 	field->fore = attribute;
528 	return E_OK;
529 }
530 
531 /*
532  * Return the foreground character attribute for the given field.
533  */
534 chtype
535 field_fore(FIELD *field)
536 {
537 	if (field == NULL)
538 		return _formi_default_field.fore;
539 	else
540 		return field->fore;
541 }
542 
543 /*
544  * Set the background character attribute for the given field.
545  */
546 int
547 set_field_back(FIELD *field, chtype attribute)
548 {
549 	if (field == NULL)
550 		_formi_default_field.back = attribute;
551 	else
552 		field->back = attribute;
553 
554 	return E_OK;
555 }
556 
557 /*
558  * Get the background character attribute for the given field.
559  */
560 chtype
561 field_back(FIELD *field)
562 {
563 	if (field == NULL)
564 		return _formi_default_field.back;
565 	else
566 		return field->back;
567 }
568 
569 /*
570  * Set the pad character for the given field.
571  */
572 int
573 set_field_pad(FIELD *field, int pad)
574 {
575 	if (field == NULL)
576 		_formi_default_field.pad = pad;
577 	else
578 		field->pad = pad;
579 
580 	return E_OK;
581 }
582 
583 /*
584  * Return the padding character for the given field.
585  */
586 int
587 field_pad(FIELD *field)
588 {
589 	if (field == NULL)
590 		return _formi_default_field.pad;
591 	else
592 		return field->pad;
593 }
594 
595 /*
596  * Set the field initialisation function hook.
597  */
598 int
599 set_field_init(FORM *form, Form_Hook function)
600 {
601 	if (form == NULL)
602 		_formi_default_form.field_init = function;
603 	else
604 		form->field_init = function;
605 
606 	return E_OK;
607 }
608 
609 /*
610  * Return the function hook for the field initialisation.
611  */
612 Form_Hook
613 field_init(FORM *form)
614 {
615 	if (form == NULL)
616 		return _formi_default_form.field_init;
617 	else
618 		return form->field_init;
619 }
620 
621 /*
622  * Set the field termination function hook.
623  */
624 int
625 set_field_term(FORM *form, Form_Hook function)
626 {
627 	if (form == NULL)
628 		_formi_default_form.field_term = function;
629 	else
630 		form->field_term = function;
631 
632 	return E_OK;
633 }
634 
635 /*
636  * Return the function hook defined for the field termination.
637  */
638 Form_Hook
639 field_term(FORM *form)
640 {
641 	if (form == NULL)
642 		return _formi_default_form.field_term;
643 	else
644 		return form->field_term;
645 }
646 
647 /*
648  * Set the page flag on the given field to indicate it is the start of a
649  * new page.
650  */
651 int
652 set_new_page(FIELD *fptr, int page)
653 {
654 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
655 
656 	if (field->parent != NULL) /* check if field is connected to a form */
657 		return E_CONNECTED;
658 
659 	field->page_break = (page != FALSE);
660 	return E_OK;
661 }
662 
663 /*
664  * Return the page status for the given field.  TRUE is returned if the
665  * field is the start of a new page.
666  */
667 int
668 new_page(FIELD *field)
669 {
670 	if (field == NULL)
671 		return _formi_default_field.page_break;
672 	else
673 		return field->page_break;
674 }
675 
676 /*
677  * Return the index of the field in the form fields array.
678  */
679 int
680 field_index(FIELD *field)
681 {
682 	if (field == NULL)
683 		return E_BAD_ARGUMENT;
684 
685 	if (field->parent == NULL)
686 		return E_NOT_CONNECTED;
687 
688 	return field->index;
689 }
690 
691 /*
692  * Internal function that does most of the work to create a new field.
693  * The new field is initialised from the information in the prototype
694  * field passed.
695  * Returns NULL on error.
696  */
697 static FIELD *
698 _formi_create_field(FIELD *prototype, int rows, int cols, int frow,
699 		    int fcol, int nrows, int nbuf)
700 {
701 	FIELD *new;
702 
703 	if ((rows <= 0) || (cols <= 0) || (frow < 0) || (fcol < 0) ||
704 	    (nrows < 0) || (nbuf < 0))
705 		return NULL;
706 
707 	if ((new = (FIELD *)malloc(sizeof(FIELD))) == NULL) {
708 		return NULL;
709 	}
710 
711 	  /* copy in the default field info */
712 	bcopy(prototype, new, sizeof(FIELD));
713 
714 	new->nbuf = nbuf + 1;
715 	new->rows = rows;
716 	new->cols = cols;
717 	new->form_row = frow;
718 	new->form_col = fcol;
719 	new->nrows = nrows;
720 	new->link = new;
721 	return new;
722 }
723 
724 /*
725  * Create a new field structure.
726  */
727 FIELD *
728 new_field(int rows, int cols, int frow, int fcol, int nrows, int nbuf)
729 {
730 	FIELD *new;
731 	size_t buf_len;
732 	int i;
733 
734 
735 	if ((new = _formi_create_field(&_formi_default_field, rows, cols,
736 				       frow, fcol, nrows, nbuf)) == NULL)
737 		return NULL;
738 
739 	buf_len = (nbuf + 1) * sizeof(FORM_STR);
740 
741 	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
742 		free(new);
743 		return NULL;
744 	}
745 
746 	  /* Initialise the strings to a zero length string */
747 	for (i = 0; i < nbuf + 1; i++) {
748 		if ((new->buffers[i].string =
749 		     (char *) malloc(sizeof(char))) == NULL) {
750 			free(new->buffers);
751 			free(new);
752 			return NULL;
753 		}
754 		new->buffers[i].string[0] = '\0';
755 		new->buffers[i].length = 0;
756 		new->buffers[i].allocated = 1;
757 	}
758 
759 	if ((new->lines = (_FORMI_FIELD_LINES *)
760 	     malloc(sizeof(struct _formi_field_lines))) == NULL) {
761 		free(new->buffers);
762 		free(new);
763 		return NULL;
764 	}
765 
766 	new->lines_alloced = 1;
767 	new->lines[0].length = 0;
768 	new->lines[0].start = 0;
769 	new->lines[0].end = 0;
770 	new->lines[0].tabs = NULL;
771 
772 	return new;
773 }
774 
775 /*
776  * Duplicate the given field, including it's buffers.
777  */
778 FIELD *
779 dup_field(FIELD *field, int frow, int fcol)
780 {
781 	FIELD *new;
782 	size_t row_len, buf_len;
783 
784 	if (field == NULL)
785 		return NULL;
786 
787 	  /* XXXX this right???? */
788 	if ((new = _formi_create_field(field, (int) field->rows,
789 				       (int ) field->cols,
790 				       frow, fcol, (int) field->nrows,
791 				       field->nbuf - 1)) == NULL)
792 		return NULL;
793 
794 	row_len = (field->rows + field->nrows + 1) * field->cols;
795 	buf_len = (field->nbuf + 1) * row_len * sizeof(FORM_STR);
796 
797 	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
798 		free(new);
799 		return NULL;
800 	}
801 
802 	  /* copy the buffers from the source field into the new copy */
803 	bcopy(field->buffers, new->buffers, buf_len);
804 
805 	return new;
806 }
807 
808 /*
809  * Create a new field at the specified location by duplicating the given
810  * field.  The buffers are shared with the parent field.
811  */
812 FIELD *
813 link_field(FIELD *field, int frow, int fcol)
814 {
815 	FIELD *new;
816 
817 	if (field == NULL)
818 		return NULL;
819 
820 	if ((new = _formi_create_field(field, (int) field->rows,
821 				       (int) field->cols,
822 				       frow, fcol, (int) field->nrows,
823 				       field->nbuf - 1)) == NULL)
824 		return NULL;
825 
826 	new->link = field->link;
827 	field->link = new;
828 
829 	  /* we are done.  The buffer pointer was copied during the field
830 	     creation. */
831 	return new;
832 }
833 
834 /*
835  * Release all storage allocated to the field
836  */
837 int
838 free_field(FIELD *field)
839 {
840 	FIELD *flink;
841 	int i;
842 	_formi_tab_t *ts, *nts;
843 
844 	if (field == NULL)
845 		return E_BAD_ARGUMENT;
846 
847 	if (field->parent != NULL)
848 		return E_CONNECTED;
849 
850 	if (field->link == field) { /* check if field linked */
851 		  /* no it is not - release the buffers */
852 		free(field->buffers);
853 		  /* free the tab structures */
854 		for (i = 0; i < field->row_count - 1; i++) {
855 			if (field->lines[i].tabs != NULL) {
856 				ts = field->lines[i].tabs;
857 				while (ts != NULL) {
858 					nts = ts->fwd;
859 					free(ts);
860 					ts = nts;
861 				}
862 			}
863 		}
864 	} else {
865 		  /* is linked, traverse the links to find the field referring
866 		   * to the one to be freed.
867 		   */
868 		for (flink = field->link; flink != field; flink = flink->link);
869 		flink->link = field->link;
870 	}
871 
872 	free(field);
873 	return E_OK;
874 }
875 
876 
877