'\" t .\"*************************************************************************** .\" Copyright (c) 1998-2010,2018 Free Software Foundation, Inc. * .\" * .\" Permission is hereby granted, free of charge, to any person obtaining a * .\" copy of this software and associated documentation files (the * .\" "Software"), to deal in the Software without restriction, including * .\" without limitation the rights to use, copy, modify, merge, publish, * .\" distribute, distribute with modifications, sublicense, and/or sell * .\" copies of the Software, and to permit persons to whom the Software is * .\" furnished to do so, subject to the following conditions: * .\" * .\" The above copyright notice and this permission notice shall be included * .\" in all copies or substantial portions of the Software. * .\" * .\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * .\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * .\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * .\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * .\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * .\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * .\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. * .\" * .\" Except as contained in this notice, the name(s) of the above copyright * .\" holders shall not be used in advertising or otherwise to promote the * .\" sale, use or other dealings in this Software without prior written * .\" authorization. * .\"*************************************************************************** .\" .\" $Id: form_fieldtype.3x,v 1.18 2018/07/28 22:08:59 tom Exp $ .TH form_fieldtype 3X "" .SH NAME \fBform_fieldtype\fR \- define validation-field types .SH SYNOPSIS \fB#include \fR .br FIELDTYPE *new_fieldtype( bool (* const field_check)(FIELD *, const void *), bool (* const char_check)(int, const void *)); .br int free_fieldtype(FIELDTYPE *fieldtype); .br int set_fieldtype_arg( FIELDTYPE *fieldtype, void *(* const make_arg)(va_list *), void *(* const copy_arg)(const void *), void (* const free_arg)(void *)); .br int set_fieldtype_choice( FIELDTYPE *fieldtype, bool (* const next_choice)(FIELD *, const void *), bool (* const prev_choice)(FIELD *, const void *)); .br FIELDTYPE *link_fieldtype(FIELDTYPE *type1, FIELDTYPE *type2); .br .SH DESCRIPTION The function \fBnew_fieldtype\fR creates a new field type usable for data validation. You supply it with \fIfield_check\fR, a predicate to check the validity of an entered data string whenever the user attempts to leave a field. The (FIELD *) argument is passed in so the validation predicate can see the field's buffer, sizes and other attributes; the second argument is an argument-block structure, about which more below. .PP You also supply \fBnew_fieldtype\fR with \fIchar_check\fR, a function to validate input characters as they are entered; it will be passed the character to be checked and a pointer to an argument-block structure. .PP The function \fBfree_fieldtype\fR frees the space allocated for a given validation type. .PP The function \fBset_fieldtype_arg\fR associates three storage-management functions with a field type. The \fImake_arg\fR function is automatically applied to the list of arguments you give \fBset_field_type\fR when attaching validation to a field; its job is to bundle these into an allocated argument-block object which can later be passed to validation predicated. The other two hook arguments should copy and free argument-block structures. They will be used by the forms-driver code. You must supply the \fImake_arg\fR function, the other two are optional, you may supply NULL for them. In this case it is assumed that \fImake_arg\fR does not allocate memory but simply loads the argument into a single scalar value. .PP The function \fBlink_fieldtype\fR creates a new field type from the two given types. They are connected by an logical 'OR'. .PP The form driver requests \fBREQ_NEXT_CHOICE\fR and \fBREQ_PREV_CHOICE\fR assume that the possible values of a field form an ordered set, and provide the forms user with a way to move through the set. The \fBset_fieldtype_choice\fR function allows forms programmers to define successor and predecessor functions for the field type. These functions take the field pointer and an argument-block structure as arguments. .SH RETURN VALUE The pointer-valued routines return NULL on error. They set errno according to their success: .TP 5 .B E_OK The routine succeeded. .TP 5 .B E_BAD_ARGUMENT Routine detected an incorrect or out-of-range argument. .TP 5 .B E_SYSTEM_ERROR System error occurred, e.g., malloc failure. .PP The integer-valued routines return one of the following codes on error: .TP 5 .B E_OK The routine succeeded. .TP 5 .B E_BAD_ARGUMENT Routine detected an incorrect or out-of-range argument. .TP 5 .B E_CONNECTED The field is already connected to a form. .TP 5 .B E_CURRENT The field is the current field. .TP 5 .B E_SYSTEM_ERROR System error occurred (see \fBerrno\fR). .SH SEE ALSO \fBcurses\fR(3X), \fBform\fR(3X). .SH NOTES The header file \fB\fR automatically includes the header file \fB\fR. .PP All of the \fB(char *)\fR arguments of these functions should actually be \fB(void *)\fR. The type has been left uncorrected for strict compatibility with System V. .SH PORTABILITY These routines emulate the System V forms library. They were not supported on Version 7 or BSD versions. .SH AUTHORS Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond.