<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <!-- * t **************************************************************************** * Copyright (c) 1998,2000,2001 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 1.9 2001/08/04 20:36:25 William.Setzer Exp @ --> <HTML> <HEAD> <TITLE>form_fieldtype 3x</TITLE><link rev=made href="mailto:bug-ncurses@gnu.org"> </HEAD> <BODY> <H1>form_fieldtype 3x</H1> <HR> <PRE> <!-- Manpage converted by man2html 3.0.1 --> </PRE> <H2>NAME</H2><PRE> <STRONG>form_fieldtype</STRONG> - define validation-field types </PRE> <H2>SYNOPSIS</H2><PRE> <STRONG>#include</STRONG> <STRONG><form.h></STRONG> FIELDTYPE *new_fieldtype( bool (* const field_check)(FIELD *, const void *), bool (* const char_check)(int, const void *)); int free_fieldtype(FIELDTYPE *fieldtype); int set_fieldtype_arg( FIELDTYPE *fieldtype, void *(* const make_arg)(va_list *), void *(* const copy_arg)(const void *), void (* const free_arg)(void *)); int set_fieldtype_choice( FIELDTYPE *fieldtype, bool (* const next_choice)(FIELD *, const void *), bool (* const prev_choice)(FIELD *, const void *)); FIELDTYPE *link_fieldtype(FIELDTYPE *type1, FIELDTYPE *type2); </PRE> <H2>DESCRIPTION</H2><PRE> The function <STRONG>new_fieldtype</STRONG> creates a new field type usable for data validation. You supply it with <EM>field</EM><STRONG>_</STRONG><EM>check</EM>, a predicate to check the validity of an entered data string whenever the user attempt 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. You also supply <STRONG>new_fieldtype</STRONG> with <EM>char</EM><STRONG>_</STRONG><EM>check</EM>, 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. The function <STRONG>free_fieldtype</STRONG> frees the space allocated for a given validation type. The function <STRONG>set_fieldtype</STRONG> associates three storage-man- agement functions with a field type. The <EM>mak</EM><STRONG>_</STRONG><EM>arg</EM> function is automatically applied to the list of arguments you give <STRONG>set_field_type</STRONG> 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 argu- ment-block structures. They will be used by the forms- driver code. You must supply the <EM>mak</EM><STRONG>_</STRONG><EM>arg</EM> function, the other two are optional, you may supply NULL for them. In this case it is assumed, that <EM>mak</EM><STRONG>_</STRONG><EM>arg</EM> doesn't allocate memory but simply loads the argument into a single scalar value. The form driver requests <STRONG>REQ_NEXT_CHOICE</STRONG> and <STRONG>REQ_PREV_CHOICE</STRONG> 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 <STRONG>set_fieldtype_choice</STRONG> func- tion allows forms programmers to define successor and pre- decessor functions for the field type. These functions take the field pointer and an argument-block structure as arguments. </PRE> <H2>RETURN VALUE</H2><PRE> The pointer-valued routines return NULL on error. The integer-valued routines return one of the following codes on error: <STRONG>E_OK</STRONG> The routine succeeded. <STRONG>E_SYSTEM_ERROR</STRONG> System error occurred (see <STRONG>errno</STRONG>). <STRONG>E_BAD_ARGUMENT</STRONG> Routine detected an incorrect or out-of-range argu- ment. <STRONG>E_CONNECTED</STRONG> The field is already connected to a form. </PRE> <H2>SEE ALSO</H2><PRE> <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>. </PRE> <H2>NOTES</H2><PRE> The header file <STRONG><form.h></STRONG> automatically includes the header file <STRONG><curses.h></STRONG>. All of the <STRONG>(char</STRONG> <STRONG>*)</STRONG> arguments of these functions should actually be <STRONG>(void</STRONG> <STRONG>*)</STRONG>. The type has been left uncorrected for strict compatibility with System V. </PRE> <H2>PORTABILITY</H2><PRE> These routines emulate the System V forms library. They were not supported on Version 7 or BSD versions. </PRE> <H2>AUTHORS</H2><PRE> Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond. </PRE> <HR> <ADDRESS> Man(1) output converted with <a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a> </ADDRESS> </BODY> </HTML>