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field.c revision 1.28
      1 /*	$NetBSD: field.c,v 1.28 2014/10/18 08:33:23 snj Exp $	*/
      2 /*-
      3  * Copyright (c) 1998-1999 Brett Lymn
      4  *                         (blymn (at) baea.com.au, brett_lymn (at) 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 1.28 2014/10/18 08:33:23 snj Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <stdlib.h>
     36 #include <strings.h>
     37 #include <stdarg.h>
     38 #include <form.h>
     39 #include "internals.h"
     40 
     41 extern FORM _formi_default_form;
     42 
     43 FIELD _formi_default_field = {
     44 	0, /* rows in the field */
     45 	0, /* columns in the field */
     46 	0, /* dynamic rows */
     47 	0, /* dynamic columns */
     48 	0, /* maximum growth */
     49 	0, /* starting row in the form subwindow */
     50 	0, /* starting column in the form subwindow */
     51 	0, /* number of off screen rows */
     52 	0, /* index of this field in form fields array. */
     53 	0, /* number of buffers associated with this field */
     54 	FALSE, /* set to true if buffer 0 has changed. */
     55 	NO_JUSTIFICATION, /* justification style of the field */
     56 	FALSE, /* set to true if field is in overlay mode */
     57 	NULL, /* pointer to the current line cursor is on */
     58 	0, /* starting char in string (horiz scroll) */
     59 	NULL, /* starting line in field (vert scroll) */
     60 	0, /* number of rows actually used in field */
     61 	0, /* actual pos of cursor in row, not same as x pos due to tabs */
     62 	0, /* x pos of cursor in field */
     63 	0, /* y pos of cursor in field */
     64 	0, /* start of a new page on the form if 1 */
     65 	0, /* number of the page this field is on */
     66 	A_NORMAL, /* character attributes for the foreground */
     67 	A_NORMAL, /* character attributes for the background */
     68 	' ', /* padding character */
     69 	DEFAULT_FORM_OPTS, /* options for the field */
     70 	NULL, /* the form this field is bound to, if any */
     71 	NULL, /* field above this one */
     72 	NULL, /* field below this one */
     73 	NULL, /* field to the left of this one */
     74 	NULL, /* field to the right of this one */
     75 	NULL,  /* user defined pointer. */
     76 	NULL, /* used if fields are linked */
     77 	NULL, /* type struct for the field */
     78 	{NULL, NULL}, /* circle queue glue for sorting fields */
     79 	NULL, /* args for field type. */
     80 	NULL, /* pointer to the array of lines structures. */
     81 	NULL, /* list of lines available for reuse */
     82 	NULL, /* array of buffers for the field */
     83 };
     84 
     85 /* internal function prototypes */
     86 static int
     87 field_buffer_init(FIELD *field, int buffer, unsigned int len);
     88 static FIELD *
     89 _formi_create_field(FIELD *, int, int, int, int, int, int);
     90 
     91 
     92 /*
     93  * Set the userptr for the field
     94  */
     95 int
     96 set_field_userptr(FIELD *field, void *ptr)
     97 {
     98 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
     99 
    100 	fp->userptr = ptr;
    101 
    102 	return E_OK;
    103 }
    104 
    105 /*
    106  * Return the userptr for the field.
    107  */
    108 
    109 void *
    110 field_userptr(FIELD *field)
    111 {
    112 	if (field == NULL)
    113 		return _formi_default_field.userptr;
    114 	else
    115 		return field->userptr;
    116 }
    117 
    118 /*
    119  * Set the options for the designated field.
    120  */
    121 int
    122 set_field_opts(FIELD *field, Form_Options options)
    123 {
    124 	int i;
    125 
    126 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
    127 
    128 	  /* not allowed to set opts if the field is the current one */
    129 	if ((field != NULL) && (field->parent != NULL) &&
    130 	    (field->parent->cur_field == field->index))
    131 		return E_CURRENT;
    132 
    133 	if ((options & O_STATIC) == O_STATIC) {
    134 		for (i = 0; i < fp->nbuf; i++) {
    135 			if (fp->buffers[i].length > fp->cols)
    136 				fp->buffers[i].string[fp->cols] = '\0';
    137 		}
    138 	}
    139 
    140 	fp->opts = options;
    141 
    142 	  /* if appropriate, redraw the field */
    143 	if ((field != NULL) && (field->parent != NULL)
    144 	    && (field->parent->posted == 1)) {
    145 		_formi_redraw_field(field->parent, field->index);
    146 		pos_form_cursor(field->parent);
    147 		wrefresh(field->parent->scrwin);
    148 	}
    149 
    150 	return E_OK;
    151 }
    152 
    153 /*
    154  * Turn on the passed field options.
    155  */
    156 int
    157 field_opts_on(FIELD *field, Form_Options options)
    158 {
    159 	int i;
    160 
    161 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
    162 
    163 	  /* not allowed to set opts if the field is the current one */
    164 	if ((field != NULL) && (field->parent != NULL) &&
    165 	    (field->parent->cur_field == field->index))
    166 		return E_CURRENT;
    167 
    168 	if ((options & O_STATIC) == O_STATIC) {
    169 		for (i = 0; i < fp->nbuf; i++) {
    170 			if (fp->buffers[i].length > fp->cols)
    171 				fp->buffers[i].string[fp->cols] = '\0';
    172 		}
    173 	}
    174 
    175 	fp->opts |= options;
    176 
    177 	  /* if appropriate, redraw the field */
    178 	if ((field != NULL) && (field->parent != NULL)
    179 	    && (field->parent->posted == 1)) {
    180 		_formi_redraw_field(field->parent, field->index);
    181 		pos_form_cursor(field->parent);
    182 		wrefresh(field->parent->scrwin);
    183 	}
    184 
    185 	return E_OK;
    186 }
    187 
    188 /*
    189  * Turn off the passed field options.
    190  */
    191 int
    192 field_opts_off(FIELD *field, Form_Options options)
    193 {
    194 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
    195 
    196 	  /* not allowed to set opts if the field is the current one */
    197 	if ((field != NULL) && (field->parent != NULL) &&
    198 	    (field->parent->cur_field == field->index))
    199 		return E_CURRENT;
    200 
    201 	fp->opts &= ~options;
    202 
    203 	  /* if appropriate, redraw the field */
    204 	if ((field != NULL) && (field->parent != NULL)
    205 	    && (field->parent->posted == 1)) {
    206 		_formi_redraw_field(field->parent, field->index);
    207 		pos_form_cursor(field->parent);
    208 		wrefresh(field->parent->scrwin);
    209 	}
    210 
    211 	return E_OK;
    212 }
    213 
    214 /*
    215  * Return the field options associated with the passed field.
    216  */
    217 Form_Options
    218 field_opts(FIELD *field)
    219 {
    220 	if (field == NULL)
    221 		return _formi_default_field.opts;
    222 	else
    223 		return field->opts;
    224 }
    225 
    226 /*
    227  * Set the justification for the passed field.
    228  */
    229 int
    230 set_field_just(FIELD *field, int justification)
    231 {
    232 	FIELD *fp = (field == NULL) ? &_formi_default_field : field;
    233 
    234 	  /*
    235 	   * not allowed to set justification if the field is
    236 	   * the current one
    237 	   */
    238 	if ((field != NULL) && (field->parent != NULL) &&
    239 	    (field->parent->cur_field == field->index))
    240 		return E_CURRENT;
    241 
    242 	if ((justification < MIN_JUST_STYLE) /* check justification valid */
    243 	    || (justification > MAX_JUST_STYLE))
    244 		return E_BAD_ARGUMENT;
    245 
    246 	  /* only allow justification on static, single row fields */
    247 	if (((fp->opts & O_STATIC) != O_STATIC) ||
    248 	    ((fp->rows + fp->nrows) > 1))
    249 		return E_BAD_ARGUMENT;
    250 
    251 	fp->justification = justification;
    252 
    253 	_formi_init_field_xpos(fp);
    254 
    255 	return E_OK;
    256 }
    257 
    258 /*
    259  * Return the justification style of the field passed.
    260  */
    261 int
    262 field_just(FIELD *field)
    263 {
    264 	if (field == NULL)
    265 		return _formi_default_field.justification;
    266 	else
    267 		return field->justification;
    268 }
    269 
    270 /*
    271  * Return information about the field passed.
    272  */
    273 int
    274 field_info(FIELD *field, int *rows, int *cols, int *frow, int *fcol,
    275 	   int *nrow, int *nbuf)
    276 {
    277 	if (field == NULL)
    278 		return E_BAD_ARGUMENT;
    279 
    280 	*rows = field->rows;
    281 	*cols = field->cols;
    282 	*frow = field->form_row;
    283 	*fcol = field->form_col;
    284 	*nrow = field->nrows;
    285 	*nbuf = field->nbuf;
    286 
    287 	return E_OK;
    288 }
    289 
    290 /*
    291  * Report the dynamic field information.
    292  */
    293 int
    294 dynamic_field_info(FIELD *field, int *drows, int *dcols, int *max)
    295 {
    296 	if (field == NULL)
    297 		return E_BAD_ARGUMENT;
    298 
    299 	if ((field->opts & O_STATIC) == O_STATIC) {
    300 		*drows = field->rows;
    301 		*dcols = field->cols;
    302 	} else {
    303 		*drows = field->drows;
    304 		*dcols = field->dcols;
    305 	}
    306 
    307 	*max = field->max;
    308 
    309 	return E_OK;
    310 }
    311 
    312 /*
    313  * Init all the field variables, perform wrapping and other tasks
    314  * after the field buffer is set.
    315  */
    316 static int
    317 field_buffer_init(FIELD *field, int buffer, unsigned int len)
    318 {
    319 	int status;
    320 	char *newp;
    321 
    322 	if (buffer == 0) {
    323 		field->start_char = 0;
    324 		field->start_line = 0;
    325 		field->row_xpos = 0;
    326 		field->cursor_xpos = 0;
    327 		field->cursor_ypos = 0;
    328 		field->row_count = 1; /* must be at least one row  XXX need to shift old rows (if any) to free list??? */
    329 		field->alines->length = len;
    330 		if ((newp = realloc(field->alines->string,
    331 				    (size_t) len + 1)) == NULL)
    332 			return E_SYSTEM_ERROR;
    333 		field->alines->string = newp;
    334 		field->alines->allocated = len + 1;
    335 		strlcpy(field->alines->string, field->buffers[buffer].string,
    336 			(size_t) len + 1);
    337 		field->alines->expanded =
    338 			_formi_tab_expanded_length(field->alines->string,
    339 						   0, field->alines->length);
    340 
    341 		field->start_line = field->alines;
    342 		field->cur_line = field->alines;
    343 
    344 		  /* we have to hope the wrap works - if it does not then the
    345 		     buffer is pretty much borked */
    346 		status = _formi_wrap_field(field, field->cur_line);
    347 		if (status != E_OK)
    348 			return status;
    349 
    350 		  /*
    351 		   * calculate the tabs for a single row field, the
    352 		   * multiline case is handled when the wrap is done.
    353 		   */
    354 		if (field->row_count == 1)
    355 			_formi_calculate_tabs(field->alines);
    356 
    357 		  /* redraw the field to reflect the new contents. If the field
    358 		   * is attached....
    359 		   */
    360 		if ((field->parent != NULL) && (field->parent->posted == 1)) {
    361 			_formi_redraw_field(field->parent, field->index);
    362 			  /* make sure cursor goes back to current field */
    363 			pos_form_cursor(field->parent);
    364 		}
    365 	}
    366 
    367 	return E_OK;
    368 }
    369 
    370 
    371 /*
    372  * Set the field buffer to the string that results from processing
    373  * the given format (fmt) using sprintf.
    374  */
    375 int
    376 set_field_printf(FIELD *field, int buffer, char *fmt, ...)
    377 {
    378 	int len;
    379 	va_list args;
    380 
    381 	if (field == NULL)
    382 		return E_BAD_ARGUMENT;
    383 
    384 	if (buffer >= field->nbuf)
    385 		return E_BAD_ARGUMENT;
    386 
    387 	va_start(args, fmt);
    388 	  /* check for buffer already existing, free the storage */
    389 	if (field->buffers[buffer].allocated != 0)
    390 		free(field->buffers[buffer].string);
    391 
    392 	len = vasprintf(&field->buffers[buffer].string, fmt, args);
    393 	va_end(args);
    394 	if (len < 0)
    395 		return E_SYSTEM_ERROR;
    396 
    397 	field->buffers[buffer].length = len;
    398 	field->buffers[buffer].allocated = len + 1;
    399 	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
    400 	    && ((field->rows + field->nrows) == 1))
    401 		len = field->cols;
    402 
    403 	field->buffers[buffer].string[len] = '\0';
    404 	return field_buffer_init(field, buffer, (unsigned int) len);
    405 }
    406 
    407 /*
    408  * Set the value of the field buffer to the value given.
    409  */
    410 
    411 int
    412 set_field_buffer(FIELD *field, int buffer, char *value)
    413 {
    414 	unsigned int len;
    415 	int status;
    416 
    417 	if (field == NULL)
    418 		return E_BAD_ARGUMENT;
    419 
    420 	if (buffer >= field->nbuf) /* make sure buffer is valid */
    421 		return E_BAD_ARGUMENT;
    422 
    423 	len = (unsigned int) strlen(value);
    424 	if (((field->opts & O_STATIC) == O_STATIC) && (len > field->cols)
    425 	    && ((field->rows + field->nrows) == 1))
    426 		len = field->cols;
    427 
    428 #ifdef DEBUG
    429 	if (_formi_create_dbg_file() != E_OK)
    430 		return E_SYSTEM_ERROR;
    431 
    432 	fprintf(dbg,
    433 		"set_field_buffer: entry: len = %d, value = %s, buffer=%d\n",
    434 		len, value, buffer);
    435 	fprintf(dbg, "set_field_buffer: entry: string = ");
    436 	if (field->buffers[buffer].string != NULL)
    437 		fprintf(dbg, "%s, len = %d\n", field->buffers[buffer].string,
    438 			field->buffers[buffer].length);
    439 	else
    440 		fprintf(dbg, "(null), len = 0\n");
    441 	fprintf(dbg, "set_field_buffer: entry: lines.len = %d\n",
    442 		field->alines[0].length);
    443 #endif
    444 
    445 	if ((field->buffers[buffer].string =
    446 	     (char *) realloc(field->buffers[buffer].string,
    447 			      (size_t) len + 1)) == NULL)
    448 		return E_SYSTEM_ERROR;
    449 
    450 	strlcpy(field->buffers[buffer].string, value, (size_t) len + 1);
    451 	field->buffers[buffer].length = len;
    452 	field->buffers[buffer].allocated = len + 1;
    453 	status = field_buffer_init(field, buffer, len);
    454 
    455 #ifdef DEBUG
    456 	fprintf(dbg, "set_field_buffer: exit: len = %d, value = %s\n",
    457 		len, value);
    458 	fprintf(dbg, "set_field_buffer: exit: string = %s, len = %d\n",
    459 		field->buffers[buffer].string, field->buffers[buffer].length);
    460 	fprintf(dbg, "set_field_buffer: exit: lines.len = %d\n",
    461 		field->alines[0].length);
    462 #endif
    463 
    464 	return status;
    465 }
    466 
    467 /*
    468  * Return the requested field buffer to the caller.
    469  */
    470 char *
    471 field_buffer(FIELD *field, int buffer)
    472 {
    473 
    474 	char *reformat, *p;
    475 	_FORMI_FIELD_LINES *linep;
    476 	size_t bufsize, pos;
    477 
    478 	if (field == NULL)
    479 		return NULL;
    480 
    481 	if (buffer >= field->nbuf)
    482 		return NULL;
    483 
    484 	  /*
    485 	   * We force a sync from the line structs to the buffer here.
    486 	   * Traditional libform say we don't need to because it is
    487 	   * done on a REQ_VALIDATE but NetBSD libform previously did
    488 	   * not enforce this because the buffer contents were always
    489 	   * current.  Changes to line handling make this no longer so
    490 	   * - the line structs may contain different data to the
    491 	   * buffer if unsynced.
    492 	   */
    493 	if (_formi_sync_buffer(field) != E_OK)
    494 		return NULL;
    495 
    496 	if ((field->opts & O_REFORMAT) != O_REFORMAT)
    497 		return field->buffers[buffer].string;
    498 
    499 	if (field->row_count <= 1)
    500 		return strdup(field->buffers[buffer].string);
    501 
    502 	/*
    503 	 * create a single string containing each line,
    504 	 * separated by newline, last line having no
    505 	 * newline, but NUL terminated.
    506 	 */
    507 	bufsize = pos = 0;
    508 	reformat = NULL;
    509 	for (linep = field->alines; linep; linep = linep->next) {
    510 		size_t len = strlen(linep->string);
    511 		if (len + 1 >= bufsize - pos) {
    512 			bufsize += MAX(1024, 2 * len);
    513 			p = realloc(reformat, bufsize);
    514 			if (p == NULL) {
    515 				free(reformat);
    516 				return NULL;
    517 			}
    518 			reformat = p;
    519 		}
    520 		memcpy(reformat + pos, linep->string, len);
    521 		pos += len;
    522 		reformat[pos++] = linep->next ? '\n' : '\0';
    523 	}
    524 	return reformat;
    525 }
    526 
    527 /*
    528  * Set the buffer 0 field status.
    529  */
    530 int
    531 set_field_status(FIELD *field, int status)
    532 {
    533 
    534 	if (field == NULL)
    535 		return E_BAD_ARGUMENT;
    536 
    537 	if (status != FALSE)
    538 		field->buf0_status = TRUE;
    539 	else
    540 		field->buf0_status = FALSE;
    541 
    542 	return E_OK;
    543 }
    544 
    545 /*
    546  * Return the buffer 0 status flag for the given field.
    547  */
    548 int
    549 field_status(FIELD *field)
    550 {
    551 
    552 	if (field == NULL) /* the default buffer 0 never changes :-) */
    553 		return FALSE;
    554 
    555 	return field->buf0_status;
    556 }
    557 
    558 /*
    559  * Set the maximum growth for a dynamic field.
    560  */
    561 int
    562 set_max_field(FIELD *fptr, int max)
    563 {
    564 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
    565 
    566 	if ((field->opts & O_STATIC) == O_STATIC) /* check if field dynamic */
    567 		return E_BAD_ARGUMENT;
    568 
    569 	if (max < 0) /* negative numbers are bad.... */
    570 		return E_BAD_ARGUMENT;
    571 
    572 	field->max = max;
    573 	return E_OK;
    574 }
    575 
    576 /*
    577  * Set the field foreground character attributes.
    578  */
    579 int
    580 set_field_fore(FIELD *fptr, chtype attribute)
    581 {
    582 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
    583 
    584 	field->fore = attribute;
    585 	return E_OK;
    586 }
    587 
    588 /*
    589  * Return the foreground character attribute for the given field.
    590  */
    591 chtype
    592 field_fore(FIELD *field)
    593 {
    594 	if (field == NULL)
    595 		return _formi_default_field.fore;
    596 	else
    597 		return field->fore;
    598 }
    599 
    600 /*
    601  * Set the background character attribute for the given field.
    602  */
    603 int
    604 set_field_back(FIELD *field, chtype attribute)
    605 {
    606 	if (field == NULL)
    607 		_formi_default_field.back = attribute;
    608 	else
    609 		field->back = attribute;
    610 
    611 	return E_OK;
    612 }
    613 
    614 /*
    615  * Get the background character attribute for the given field.
    616  */
    617 chtype
    618 field_back(FIELD *field)
    619 {
    620 	if (field == NULL)
    621 		return _formi_default_field.back;
    622 	else
    623 		return field->back;
    624 }
    625 
    626 /*
    627  * Set the pad character for the given field.
    628  */
    629 int
    630 set_field_pad(FIELD *field, int pad)
    631 {
    632 	if (field == NULL)
    633 		_formi_default_field.pad = pad;
    634 	else
    635 		field->pad = pad;
    636 
    637 	return E_OK;
    638 }
    639 
    640 /*
    641  * Return the padding character for the given field.
    642  */
    643 int
    644 field_pad(FIELD *field)
    645 {
    646 	if (field == NULL)
    647 		return _formi_default_field.pad;
    648 	else
    649 		return field->pad;
    650 }
    651 
    652 /*
    653  * Set the field initialisation function hook.
    654  */
    655 int
    656 set_field_init(FORM *form, Form_Hook function)
    657 {
    658 	if (form == NULL)
    659 		_formi_default_form.field_init = function;
    660 	else
    661 		form->field_init = function;
    662 
    663 	return E_OK;
    664 }
    665 
    666 /*
    667  * Return the function hook for the field initialisation.
    668  */
    669 Form_Hook
    670 field_init(FORM *form)
    671 {
    672 	if (form == NULL)
    673 		return _formi_default_form.field_init;
    674 	else
    675 		return form->field_init;
    676 }
    677 
    678 /*
    679  * Set the field termination function hook.
    680  */
    681 int
    682 set_field_term(FORM *form, Form_Hook function)
    683 {
    684 	if (form == NULL)
    685 		_formi_default_form.field_term = function;
    686 	else
    687 		form->field_term = function;
    688 
    689 	return E_OK;
    690 }
    691 
    692 /*
    693  * Return the function hook defined for the field termination.
    694  */
    695 Form_Hook
    696 field_term(FORM *form)
    697 {
    698 	if (form == NULL)
    699 		return _formi_default_form.field_term;
    700 	else
    701 		return form->field_term;
    702 }
    703 
    704 /*
    705  * Set the page flag on the given field to indicate it is the start of a
    706  * new page.
    707  */
    708 int
    709 set_new_page(FIELD *fptr, int page)
    710 {
    711 	FIELD *field = (fptr == NULL)? &_formi_default_field : fptr;
    712 
    713 	if (field->parent != NULL) /* check if field is connected to a form */
    714 		return E_CONNECTED;
    715 
    716 	field->page_break = (page != FALSE);
    717 	return E_OK;
    718 }
    719 
    720 /*
    721  * Return the page status for the given field.  TRUE is returned if the
    722  * field is the start of a new page.
    723  */
    724 int
    725 new_page(FIELD *field)
    726 {
    727 	if (field == NULL)
    728 		return _formi_default_field.page_break;
    729 	else
    730 		return field->page_break;
    731 }
    732 
    733 /*
    734  * Return the index of the field in the form fields array.
    735  */
    736 int
    737 field_index(FIELD *field)
    738 {
    739 	if (field == NULL)
    740 		return E_BAD_ARGUMENT;
    741 
    742 	if (field->parent == NULL)
    743 		return E_NOT_CONNECTED;
    744 
    745 	return field->index;
    746 }
    747 
    748 /*
    749  * Internal function that does most of the work to create a new field.
    750  * The new field is initialised from the information in the prototype
    751  * field passed.
    752  * Returns NULL on error.
    753  */
    754 static FIELD *
    755 _formi_create_field(FIELD *prototype, int rows, int cols, int frow,
    756 		    int fcol, int nrows, int nbuf)
    757 {
    758 	FIELD *new;
    759 
    760 	if ((rows <= 0) || (cols <= 0) || (frow < 0) || (fcol < 0) ||
    761 	    (nrows < 0) || (nbuf < 0))
    762 		return NULL;
    763 
    764 	if ((new = (FIELD *)malloc(sizeof(FIELD))) == NULL) {
    765 		return NULL;
    766 	}
    767 
    768 	  /* copy in the default field info */
    769 	bcopy(prototype, new, sizeof(FIELD));
    770 
    771 	new->nbuf = nbuf + 1;
    772 	new->rows = rows;
    773 	new->cols = cols;
    774 	new->form_row = frow;
    775 	new->form_col = fcol;
    776 	new->nrows = nrows;
    777 	new->link = new;
    778 	return new;
    779 }
    780 
    781 /*
    782  * Create a new field structure.
    783  */
    784 FIELD *
    785 new_field(int rows, int cols, int frow, int fcol, int nrows, int nbuf)
    786 {
    787 	FIELD *new;
    788 	size_t buf_len;
    789 	int i;
    790 
    791 
    792 	if ((new = _formi_create_field(&_formi_default_field, rows, cols,
    793 				       frow, fcol, nrows, nbuf)) == NULL)
    794 		return NULL;
    795 
    796 	buf_len = (nbuf + 1) * sizeof(FORM_STR);
    797 
    798 	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
    799 		free(new);
    800 		return NULL;
    801 	}
    802 
    803 	  /* Initialise the strings to a zero length string */
    804 	for (i = 0; i < nbuf + 1; i++) {
    805 		if ((new->buffers[i].string =
    806 		     (char *) malloc(sizeof(char))) == NULL) {
    807 			free(new->buffers);
    808 			free(new);
    809 			return NULL;
    810 		}
    811 		new->buffers[i].string[0] = '\0';
    812 		new->buffers[i].length = 0;
    813 		new->buffers[i].allocated = 1;
    814 	}
    815 
    816 	if ((new->alines = (_FORMI_FIELD_LINES *)
    817 	     malloc(sizeof(struct _formi_field_lines))) == NULL) {
    818 		free(new->buffers);
    819 		free(new);
    820 		return NULL;
    821 	}
    822 
    823 	new->alines->prev = NULL;
    824 	new->alines->next = NULL;
    825 	new->alines->allocated = 0;
    826 	new->alines->length = 0;
    827 	new->alines->expanded = 0;
    828 	new->alines->string = NULL;
    829 	new->alines->hard_ret = FALSE;
    830 	new->alines->tabs = NULL;
    831 	new->start_line = new->alines;
    832 	new->cur_line = new->alines;
    833 
    834 	return new;
    835 }
    836 
    837 /*
    838  * Duplicate the given field, including its buffers.
    839  */
    840 FIELD *
    841 dup_field(FIELD *field, int frow, int fcol)
    842 {
    843 	FIELD *new;
    844 	size_t row_len, buf_len;
    845 
    846 	if (field == NULL)
    847 		return NULL;
    848 
    849 	  /* XXXX this right???? */
    850 	if ((new = _formi_create_field(field, (int) field->rows,
    851 				       (int ) field->cols,
    852 				       frow, fcol, (int) field->nrows,
    853 				       field->nbuf - 1)) == NULL)
    854 		return NULL;
    855 
    856 	row_len = (field->rows + field->nrows + 1) * field->cols;
    857 	buf_len = (field->nbuf + 1) * row_len * sizeof(FORM_STR);
    858 
    859 	if ((new->buffers = (FORM_STR *)malloc(buf_len)) == NULL) {
    860 		free(new);
    861 		return NULL;
    862 	}
    863 
    864 	  /* copy the buffers from the source field into the new copy */
    865 	bcopy(field->buffers, new->buffers, buf_len);
    866 
    867 	return new;
    868 }
    869 
    870 /*
    871  * Create a new field at the specified location by duplicating the given
    872  * field.  The buffers are shared with the parent field.
    873  */
    874 FIELD *
    875 link_field(FIELD *field, int frow, int fcol)
    876 {
    877 	FIELD *new;
    878 
    879 	if (field == NULL)
    880 		return NULL;
    881 
    882 	if ((new = _formi_create_field(field, (int) field->rows,
    883 				       (int) field->cols,
    884 				       frow, fcol, (int) field->nrows,
    885 				       field->nbuf - 1)) == NULL)
    886 		return NULL;
    887 
    888 	new->link = field->link;
    889 	field->link = new;
    890 
    891 	  /* we are done.  The buffer pointer was copied during the field
    892 	     creation. */
    893 	return new;
    894 }
    895 
    896 /*
    897  * Release all storage allocated to the field
    898  */
    899 int
    900 free_field(FIELD *field)
    901 {
    902 	FIELD *flink;
    903 	int i;
    904 	_formi_tab_t *ts, *nts;
    905 
    906 	if (field == NULL)
    907 		return E_BAD_ARGUMENT;
    908 
    909 	if (field->parent != NULL)
    910 		return E_CONNECTED;
    911 
    912 	if (field->link == field) { /* check if field linked */
    913 		  /* no it is not - release the buffers */
    914 		free(field->buffers);
    915 		  /* free the tab structures */
    916 		for (i = 0; i < field->row_count - 1; i++) {
    917 			if (field->alines[i].tabs != NULL) {
    918 				ts = field->alines[i].tabs;
    919 				while (ts != NULL) {
    920 					nts = ts->fwd;
    921 					free(ts);
    922 					ts = nts;
    923 				}
    924 			}
    925 		}
    926 	} else {
    927 		  /* is linked, traverse the links to find the field referring
    928 		   * to the one to be freed.
    929 		   */
    930 		for (flink = field->link; flink != field; flink = flink->link);
    931 		flink->link = field->link;
    932 	}
    933 
    934 	free(field);
    935 	return E_OK;
    936 }
    937 
    938 
    939