field.c revision 1.25
1/*	$NetBSD: field.c,v 1.25 2010/02/03 15:34:43 roy 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 1.25 2010/02/03 15:34:43 roy Exp $");
33
34#include <stdlib.h>
35#include <strings.h>
36#include <stdarg.h>
37#include <form.h>
38#include "internals.h"
39
40extern FORM _formi_default_form;
41
42FIELD _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	NULL, /* pointer to the current line cursor is on */
57	0, /* starting char in string (horiz scroll) */
58	NULL, /* starting line in field (vert scroll) */
59	0, /* number of rows actually used in field */
60	0, /* actual pos of cursor in row, not same as x pos due to tabs */
61	0, /* x pos of cursor in field */
62	0, /* y pos of cursor in field */
63	0, /* start of a new page on the form if 1 */
64	0, /* number of the page this field is on */
65	A_NORMAL, /* character attributes for the foreground */
66	A_NORMAL, /* character attributes for the background */
67	' ', /* padding character */
68	DEFAULT_FORM_OPTS, /* options for the field */
69	NULL, /* the form this field is bound to, if any */
70	NULL, /* field above this one */
71	NULL, /* field below this one */
72	NULL, /* field to the left of this one */
73	NULL, /* field to the right of this one */
74	NULL,  /* user defined pointer. */
75	NULL, /* used if fields are linked */
76	NULL, /* type struct for the field */
77	{NULL, NULL}, /* circle queue glue for sorting fields */
78	NULL, /* args for field type. */
79	NULL, /* pointer to the array of lines structures. */
80	NULL, /* list of lines available for reuse */
81	NULL, /* array of buffers for the field */
82};
83
84/* internal function prototypes */
85static int
86field_buffer_init(FIELD *field, int buffer, unsigned int len);
87static FIELD *
88_formi_create_field(FIELD *, int, int, int, int, int, int);
89
90
91/*
92 * Set the userptr for the field
93 */
94int
95set_field_userptr(FIELD *field, void *ptr)
96{
97	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
98
99	fp->userptr = ptr;
100
101	return E_OK;
102}
103
104/*
105 * Return the userptr for the field.
106 */
107
108void *
109field_userptr(FIELD *field)
110{
111	if (field == NULL)
112		return _formi_default_field.userptr;
113	else
114		return field->userptr;
115}
116
117/*
118 * Set the options for the designated field.
119 */
120int
121set_field_opts(FIELD *field, Form_Options options)
122{
123	int i;
124
125	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
126
127	  /* not allowed to set opts if the field is the current one */
128	if ((field != NULL) && (field->parent != NULL) &&
129	    (field->parent->cur_field == field->index))
130		return E_CURRENT;
131
132	if ((options & O_STATIC) == O_STATIC) {
133		for (i = 0; i < fp->nbuf; i++) {
134			if (fp->buffers[i].length > fp->cols)
135				fp->buffers[i].string[fp->cols] = '\0';
136		}
137	}
138
139	fp->opts = options;
140
141	  /* if appropriate, redraw the field */
142	if ((field != NULL) && (field->parent != NULL)
143	    && (field->parent->posted == 1)) {
144		_formi_redraw_field(field->parent, field->index);
145		pos_form_cursor(field->parent);
146		wrefresh(field->parent->scrwin);
147	}
148
149	return E_OK;
150}
151
152/*
153 * Turn on the passed field options.
154 */
155int
156field_opts_on(FIELD *field, Form_Options options)
157{
158	int i;
159
160	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
161
162	  /* not allowed to set opts if the field is the current one */
163	if ((field != NULL) && (field->parent != NULL) &&
164	    (field->parent->cur_field == field->index))
165		return E_CURRENT;
166
167	if ((options & O_STATIC) == O_STATIC) {
168		for (i = 0; i < fp->nbuf; i++) {
169			if (fp->buffers[i].length > fp->cols)
170				fp->buffers[i].string[fp->cols] = '\0';
171		}
172	}
173
174	fp->opts |= options;
175
176	  /* if appropriate, redraw the field */
177	if ((field != NULL) && (field->parent != NULL)
178	    && (field->parent->posted == 1)) {
179		_formi_redraw_field(field->parent, field->index);
180		pos_form_cursor(field->parent);
181		wrefresh(field->parent->scrwin);
182	}
183
184	return E_OK;
185}
186
187/*
188 * Turn off the passed field options.
189 */
190int
191field_opts_off(FIELD *field, Form_Options options)
192{
193	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
194
195	  /* not allowed to set opts if the field is the current one */
196	if ((field != NULL) && (field->parent != NULL) &&
197	    (field->parent->cur_field == field->index))
198		return E_CURRENT;
199
200	fp->opts &= ~options;
201
202	  /* if appropriate, redraw the field */
203	if ((field != NULL) && (field->parent != NULL)
204	    && (field->parent->posted == 1)) {
205		_formi_redraw_field(field->parent, field->index);
206		pos_form_cursor(field->parent);
207		wrefresh(field->parent->scrwin);
208	}
209
210	return E_OK;
211}
212
213/*
214 * Return the field options associated with the passed field.
215 */
216Form_Options
217field_opts(FIELD *field)
218{
219	if (field == NULL)
220		return _formi_default_field.opts;
221	else
222		return field->opts;
223}
224
225/*
226 * Set the justification for the passed field.
227 */
228int
229set_field_just(FIELD *field, int justification)
230{
231	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
232
233	  /*
234	   * not allowed to set justification if the field is
235	   * the current one
236	   */
237	if ((field != NULL) && (field->parent != NULL) &&
238	    (field->parent->cur_field == field->index))
239		return E_CURRENT;
240
241	if ((justification < MIN_JUST_STYLE) /* check justification valid */
242	    || (justification > MAX_JUST_STYLE))
243		return E_BAD_ARGUMENT;
244
245	  /* only allow justification on static, single row fields */
246	if (((fp->opts & O_STATIC) != O_STATIC) ||
247	    ((fp->rows + fp->nrows) > 1))
248		return E_BAD_ARGUMENT;
249
250	fp->justification = justification;
251
252	_formi_init_field_xpos(fp);
253
254	return E_OK;
255}
256
257/*
258 * Return the justification style of the field passed.
259 */
260int
261field_just(FIELD *field)
262{
263	if (field == NULL)
264		return _formi_default_field.justification;
265	else
266		return field->justification;
267}
268
269/*
270 * Return information about the field passed.
271 */
272int
273field_info(FIELD *field, int *rows, int *cols, int *frow, int *fcol,
274	   int *nrow, int *nbuf)
275{
276	if (field == NULL)
277		return E_BAD_ARGUMENT;
278
279	*rows = field->rows;
280	*cols = field->cols;
281	*frow = field->form_row;
282	*fcol = field->form_col;
283	*nrow = field->nrows;
284	*nbuf = field->nbuf;
285
286	return E_OK;
287}
288
289/*
290 * Report the dynamic field information.
291 */
292int
293dynamic_field_info(FIELD *field, int *drows, int *dcols, int *max)
294{
295	if (field == NULL)
296		return E_BAD_ARGUMENT;
297
298	if ((field->opts & O_STATIC) == O_STATIC) {
299		*drows = field->rows;
300		*dcols = field->cols;
301	} else {
302		*drows = field->drows;
303		*dcols = field->dcols;
304	}
305
306	*max = field->max;
307
308	return E_OK;
309}
310
311/*
312 * Init all the field variables, perform wrapping and other tasks
313 * after the field buffer is set.
314 */
315static int
316field_buffer_init(FIELD *field, int buffer, unsigned int len)
317{
318	int status;
319	char *newp;
320
321	if (buffer == 0) {
322		field->start_char = 0;
323		field->start_line = 0;
324		field->row_xpos = 0;
325		field->cursor_xpos = 0;
326		field->cursor_ypos = 0;
327		field->row_count = 1; /* must be at least one row  XXX need to shift old rows (if any) to free list??? */
328		field->alines->length = len;
329		if ((newp = realloc(field->alines->string,
330				    (size_t) len + 1)) == NULL)
331			return E_SYSTEM_ERROR;
332		field->alines->string = newp;
333		field->alines->allocated = len + 1;
334		strlcpy(field->alines->string, field->buffers[buffer].string,
335			(size_t) len + 1);
336		field->alines->expanded =
337			_formi_tab_expanded_length(field->alines->string,
338						   0, field->alines->length);
339
340		field->start_line = field->alines;
341		field->cur_line = field->alines;
342
343		  /* we have to hope the wrap works - if it does not then the
344		     buffer is pretty much borked */
345		status = _formi_wrap_field(field, field->cur_line);
346		if (status != E_OK)
347			return status;
348
349		  /*
350		   * calculate the tabs for a single row field, the
351		   * multiline case is handled when the wrap is done.
352		   */
353		if (field->row_count == 1)
354			_formi_calculate_tabs(field->alines);
355
356		  /* redraw the field to reflect the new contents. If the field
357		   * is attached....
358		   */
359		if ((field->parent != NULL) && (field->parent->posted == 1)) {
360			_formi_redraw_field(field->parent, field->index);
361			  /* make sure cursor goes back to current field */
362			pos_form_cursor(field->parent);
363		}
364	}
365
366	return E_OK;
367}
368
369
370/*
371 * Set the field buffer to the string that results from processing
372 * the given format (fmt) using sprintf.
373 */
374int
375set_field_printf(FIELD *field, int buffer, char *fmt, ...)
376{
377	int len;
378	va_list args;
379
380	if (field == NULL)
381		return E_BAD_ARGUMENT;
382
383	if (buffer >= field->nbuf)
384		return E_BAD_ARGUMENT;
385
386	va_start(args, fmt);
387	  /* check for buffer already existing, free the storage */
388	if (field->buffers[buffer].allocated != 0)
389		free(field->buffers[buffer].string);
390
391	len = vasprintf(&field->buffers[buffer].string, fmt, args);
392	va_end(args);
393	if (len < 0)
394		return E_SYSTEM_ERROR;
395
396	field->buffers[buffer].length = len;
397	field->buffers[buffer].allocated = len + 1;
398	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
399	    && ((field->rows + field->nrows) == 1))
400		len = field->cols;
401
402	field->buffers[buffer].string[len] = '\0';
403	return field_buffer_init(field, buffer, (unsigned int) len);
404}
405
406/*
407 * Set the value of the field buffer to the value given.
408 */
409
410int
411set_field_buffer(FIELD *field, int buffer, char *value)
412{
413	unsigned int len;
414	int status;
415
416	if (field == NULL)
417		return E_BAD_ARGUMENT;
418
419	if (buffer >= field->nbuf) /* make sure buffer is valid */
420		return E_BAD_ARGUMENT;
421
422	len = (unsigned int) strlen(value);
423	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
424	    && ((field->rows + field->nrows) == 1))
425		len = field->cols;
426
427#ifdef DEBUG
428	if (_formi_create_dbg_file() != E_OK)
429		return E_SYSTEM_ERROR;
430
431	fprintf(dbg,
432		"set_field_buffer: entry: len = %d, value = %s, buffer=%d\n",
433		len, value, buffer);
434	fprintf(dbg, "set_field_buffer: entry: string = ");
435	if (field->buffers[buffer].string != NULL)
436		fprintf(dbg, "%s, len = %d\n", field->buffers[buffer].string,
437			field->buffers[buffer].length);
438	else
439		fprintf(dbg, "(null), len = 0\n");
440	fprintf(dbg, "set_field_buffer: entry: lines.len = %d\n",
441		field->alines[0].length);
442#endif
443
444	if ((field->buffers[buffer].string =
445	     (char *) realloc(field->buffers[buffer].string,
446			      (size_t) len + 1)) == NULL)
447		return E_SYSTEM_ERROR;
448
449	strlcpy(field->buffers[buffer].string, value, (size_t) len + 1);
450	field->buffers[buffer].length = len;
451	field->buffers[buffer].allocated = len + 1;
452	status = field_buffer_init(field, buffer, len);
453
454#ifdef DEBUG
455	fprintf(dbg, "set_field_buffer: exit: len = %d, value = %s\n",
456		len, value);
457	fprintf(dbg, "set_field_buffer: exit: string = %s, len = %d\n",
458		field->buffers[buffer].string, field->buffers[buffer].length);
459	fprintf(dbg, "set_field_buffer: exit: lines.len = %d\n",
460		field->alines[0].length);
461#endif
462
463	return status;
464}
465
466/*
467 * Return the requested field buffer to the caller.
468 */
469char *
470field_buffer(FIELD *field, int buffer)
471{
472
473	char *reformat, *p;
474	_FORMI_FIELD_LINES *linep;
475
476	if (field == NULL)
477		return NULL;
478
479	if (buffer >= field->nbuf)
480		return NULL;
481
482	  /*
483	   * We force a sync from the line structs to the buffer here.
484	   * Traditional libform say we don't need to because it is
485	   * done on a REQ_VALIDATE but NetBSD libform previously did
486	   * not enforce this because the buffer contents were always
487	   * current.  Changes to line handling make this no longer so
488	   * - the line structs may contain different data to the
489	   * buffer if unsynced.
490	   */
491	if (_formi_sync_buffer(field) != E_OK)
492		return NULL;
493
494	if ((field->opts & O_REFORMAT) != O_REFORMAT) {
495		return field->buffers[buffer].string;
496	} else {
497		if (field->row_count > 1) {
498			  /* reformat */
499			reformat = (char *)
500				malloc(strlen(field->buffers[buffer].string)
501				       + ((field->row_count - 1)
502					  * sizeof(char)) + 1);
503
504			if (reformat == NULL)
505				return NULL;
506
507			  /*
508			   * foreach row copy line, append newline, no
509			   * newline on last row.
510			   */
511			p = reformat;
512			linep = field->alines;
513
514			do
515			{
516				if (linep->length != 0) {
517					strncpy(p, linep->string,
518						(size_t) linep->length);
519					p += linep->length;
520				}
521
522				linep = linep->next;
523				if (linep != NULL)
524					*p = '\n';
525				p++;
526			}
527			while (linep != NULL);
528
529			p = '\0';
530			return reformat;
531		} else {
532			asprintf(&reformat, "%s",
533				 field->buffers[buffer].string);
534			return reformat;
535		}
536	}
537}
538
539/*
540 * Set the buffer 0 field status.
541 */
542int
543set_field_status(FIELD *field, int status)
544{
545
546	if (field == NULL)
547		return E_BAD_ARGUMENT;
548
549	if (status != FALSE)
550		field->buf0_status = TRUE;
551	else
552		field->buf0_status = FALSE;
553
554	return E_OK;
555}
556
557/*
558 * Return the buffer 0 status flag for the given field.
559 */
560int
561field_status(FIELD *field)
562{
563
564	if (field == NULL) /* the default buffer 0 never changes :-) */
565		return FALSE;
566
567	return field->buf0_status;
568}
569
570/*
571 * Set the maximum growth for a dynamic field.
572 */
573int
574set_max_field(FIELD *fptr, int max)
575{
576	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
577
578	if ((field->opts & O_STATIC) == O_STATIC) /* check if field dynamic */
579		return E_BAD_ARGUMENT;
580
581	if (max < 0) /* negative numbers are bad.... */
582		return E_BAD_ARGUMENT;
583
584	field->max = max;
585	return E_OK;
586}
587
588/*
589 * Set the field foreground character attributes.
590 */
591int
592set_field_fore(FIELD *fptr, chtype attribute)
593{
594	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
595
596	field->fore = attribute;
597	return E_OK;
598}
599
600/*
601 * Return the foreground character attribute for the given field.
602 */
603chtype
604field_fore(FIELD *field)
605{
606	if (field == NULL)
607		return _formi_default_field.fore;
608	else
609		return field->fore;
610}
611
612/*
613 * Set the background character attribute for the given field.
614 */
615int
616set_field_back(FIELD *field, chtype attribute)
617{
618	if (field == NULL)
619		_formi_default_field.back = attribute;
620	else
621		field->back = attribute;
622
623	return E_OK;
624}
625
626/*
627 * Get the background character attribute for the given field.
628 */
629chtype
630field_back(FIELD *field)
631{
632	if (field == NULL)
633		return _formi_default_field.back;
634	else
635		return field->back;
636}
637
638/*
639 * Set the pad character for the given field.
640 */
641int
642set_field_pad(FIELD *field, int pad)
643{
644	if (field == NULL)
645		_formi_default_field.pad = pad;
646	else
647		field->pad = pad;
648
649	return E_OK;
650}
651
652/*
653 * Return the padding character for the given field.
654 */
655int
656field_pad(FIELD *field)
657{
658	if (field == NULL)
659		return _formi_default_field.pad;
660	else
661		return field->pad;
662}
663
664/*
665 * Set the field initialisation function hook.
666 */
667int
668set_field_init(FORM *form, Form_Hook function)
669{
670	if (form == NULL)
671		_formi_default_form.field_init = function;
672	else
673		form->field_init = function;
674
675	return E_OK;
676}
677
678/*
679 * Return the function hook for the field initialisation.
680 */
681Form_Hook
682field_init(FORM *form)
683{
684	if (form == NULL)
685		return _formi_default_form.field_init;
686	else
687		return form->field_init;
688}
689
690/*
691 * Set the field termination function hook.
692 */
693int
694set_field_term(FORM *form, Form_Hook function)
695{
696	if (form == NULL)
697		_formi_default_form.field_term = function;
698	else
699		form->field_term = function;
700
701	return E_OK;
702}
703
704/*
705 * Return the function hook defined for the field termination.
706 */
707Form_Hook
708field_term(FORM *form)
709{
710	if (form == NULL)
711		return _formi_default_form.field_term;
712	else
713		return form->field_term;
714}
715
716/*
717 * Set the page flag on the given field to indicate it is the start of a
718 * new page.
719 */
720int
721set_new_page(FIELD *fptr, int page)
722{
723	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
724
725	if (field->parent != NULL) /* check if field is connected to a form */
726		return E_CONNECTED;
727
728	field->page_break = (page != FALSE);
729	return E_OK;
730}
731
732/*
733 * Return the page status for the given field.  TRUE is returned if the
734 * field is the start of a new page.
735 */
736int
737new_page(FIELD *field)
738{
739	if (field == NULL)
740		return _formi_default_field.page_break;
741	else
742		return field->page_break;
743}
744
745/*
746 * Return the index of the field in the form fields array.
747 */
748int
749field_index(FIELD *field)
750{
751	if (field == NULL)
752		return E_BAD_ARGUMENT;
753
754	if (field->parent == NULL)
755		return E_NOT_CONNECTED;
756
757	return field->index;
758}
759
760/*
761 * Internal function that does most of the work to create a new field.
762 * The new field is initialised from the information in the prototype
763 * field passed.
764 * Returns NULL on error.
765 */
766static FIELD *
767_formi_create_field(FIELD *prototype, int rows, int cols, int frow,
768		    int fcol, int nrows, int nbuf)
769{
770	FIELD *new;
771
772	if ((rows <= 0) || (cols <= 0) || (frow < 0) || (fcol < 0) ||
773	    (nrows < 0) || (nbuf < 0))
774		return NULL;
775
776	if ((new = (FIELD *)malloc(sizeof(FIELD))) == NULL) {
777		return NULL;
778	}
779
780	  /* copy in the default field info */
781	bcopy(prototype, new, sizeof(FIELD));
782
783	new->nbuf = nbuf + 1;
784	new->rows = rows;
785	new->cols = cols;
786	new->form_row = frow;
787	new->form_col = fcol;
788	new->nrows = nrows;
789	new->link = new;
790	return new;
791}
792
793/*
794 * Create a new field structure.
795 */
796FIELD *
797new_field(int rows, int cols, int frow, int fcol, int nrows, int nbuf)
798{
799	FIELD *new;
800	size_t buf_len;
801	int i;
802
803
804	if ((new = _formi_create_field(&_formi_default_field, rows, cols,
805				       frow, fcol, nrows, nbuf)) == NULL)
806		return NULL;
807
808	buf_len = (nbuf + 1) * sizeof(FORM_STR);
809
810	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
811		free(new);
812		return NULL;
813	}
814
815	  /* Initialise the strings to a zero length string */
816	for (i = 0; i < nbuf + 1; i++) {
817		if ((new->buffers[i].string =
818		     (char *) malloc(sizeof(char))) == NULL) {
819			free(new->buffers);
820			free(new);
821			return NULL;
822		}
823		new->buffers[i].string[0] = '\0';
824		new->buffers[i].length = 0;
825		new->buffers[i].allocated = 1;
826	}
827
828	if ((new->alines = (_FORMI_FIELD_LINES *)
829	     malloc(sizeof(struct _formi_field_lines))) == NULL) {
830		free(new->buffers);
831		free(new);
832		return NULL;
833	}
834
835	new->alines->prev = NULL;
836	new->alines->next = NULL;
837	new->alines->allocated = 0;
838	new->alines->length = 0;
839	new->alines->expanded = 0;
840	new->alines->string = NULL;
841	new->alines->hard_ret = FALSE;
842	new->alines->tabs = NULL;
843	new->start_line = new->alines;
844	new->cur_line = new->alines;
845
846	return new;
847}
848
849/*
850 * Duplicate the given field, including it's buffers.
851 */
852FIELD *
853dup_field(FIELD *field, int frow, int fcol)
854{
855	FIELD *new;
856	size_t row_len, buf_len;
857
858	if (field == NULL)
859		return NULL;
860
861	  /* XXXX this right???? */
862	if ((new = _formi_create_field(field, (int) field->rows,
863				       (int ) field->cols,
864				       frow, fcol, (int) field->nrows,
865				       field->nbuf - 1)) == NULL)
866		return NULL;
867
868	row_len = (field->rows + field->nrows + 1) * field->cols;
869	buf_len = (field->nbuf + 1) * row_len * sizeof(FORM_STR);
870
871	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
872		free(new);
873		return NULL;
874	}
875
876	  /* copy the buffers from the source field into the new copy */
877	bcopy(field->buffers, new->buffers, buf_len);
878
879	return new;
880}
881
882/*
883 * Create a new field at the specified location by duplicating the given
884 * field.  The buffers are shared with the parent field.
885 */
886FIELD *
887link_field(FIELD *field, int frow, int fcol)
888{
889	FIELD *new;
890
891	if (field == NULL)
892		return NULL;
893
894	if ((new = _formi_create_field(field, (int) field->rows,
895				       (int) field->cols,
896				       frow, fcol, (int) field->nrows,
897				       field->nbuf - 1)) == NULL)
898		return NULL;
899
900	new->link = field->link;
901	field->link = new;
902
903	  /* we are done.  The buffer pointer was copied during the field
904	     creation. */
905	return new;
906}
907
908/*
909 * Release all storage allocated to the field
910 */
911int
912free_field(FIELD *field)
913{
914	FIELD *flink;
915	int i;
916	_formi_tab_t *ts, *nts;
917
918	if (field == NULL)
919		return E_BAD_ARGUMENT;
920
921	if (field->parent != NULL)
922		return E_CONNECTED;
923
924	if (field->link == field) { /* check if field linked */
925		  /* no it is not - release the buffers */
926		free(field->buffers);
927		  /* free the tab structures */
928		for (i = 0; i < field->row_count - 1; i++) {
929			if (field->alines[i].tabs != NULL) {
930				ts = field->alines[i].tabs;
931				while (ts != NULL) {
932					nts = ts->fwd;
933					free(ts);
934					ts = nts;
935				}
936			}
937		}
938	} else {
939		  /* is linked, traverse the links to find the field referring
940		   * to the one to be freed.
941		   */
942		for (flink = field->link; flink != field; flink = flink->link);
943		flink->link = field->link;
944	}
945
946	free(field);
947	return E_OK;
948}
949
950
951