doc/html/man/form_fieldtype.3x.html

   1 <!--
   2   ****************************************************************************
   3   * Copyright 2018-2023,2024 Thomas E. Dickey                                *
   4   * Copyright 1998-2006,2010 Free Software Foundation, Inc.                  *
   5   *                                                                          *
   6   * Permission is hereby granted, free of charge, to any person obtaining a  *
   7   * copy of this software and associated documentation files (the            *
   8   * "Software"), to deal in the Software without restriction, including      *
   9   * without limitation the rights to use, copy, modify, merge, publish,      *
  10   * distribute, distribute with modifications, sublicense, and/or sell       *
  11   * copies of the Software, and to permit persons to whom the Software is    *
  12   * furnished to do so, subject to the following conditions:                 *
  13   *                                                                          *
  14   * The above copyright notice and this permission notice shall be included  *
  15   * in all copies or substantial portions of the Software.                   *
  16   *                                                                          *
  17   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  18   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  19   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  20   * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  21   * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
  22   * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  23   * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  24   *                                                                          *
  25   * Except as contained in this notice, the name(s) of the above copyright   *
  26   * holders shall not be used in advertising or otherwise to promote the     *
  27   * sale, use or other dealings in this Software without prior written       *
  28   * authorization.                                                           *
  29   ****************************************************************************
  30   * @Id: form_fieldtype.3x,v 1.46 2024/03/16 15:35:01 tom Exp @
  31 -->
  32 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
  33 <HTML>
  34 <HEAD>
  35 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
  36 <meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
  37 <TITLE>form_fieldtype 3x 2024-03-16 ncurses 6.5 Library calls</TITLE>
  38 <link rel="author" href="mailto:bug-ncurses@gnu.org">
  39
  40 </HEAD>
  41 <BODY>
  42 <H1 class="no-header">form_fieldtype 3x 2024-03-16 ncurses 6.5 Library calls</H1>
  43 <PRE>
  44 <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>               Library calls              <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
  45
  46
  47
  48
  49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
  50        <STRONG>form_fieldtype</STRONG> - define validation-field types
  51
  52
  53 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
  54        <STRONG>#include</STRONG> <STRONG>&lt;form.h&gt;</STRONG>
  55
  56        <STRONG>FIELDTYPE</STRONG> <STRONG>*new_fieldtype(</STRONG>
  57            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>field</EM><STRONG>_</STRONG><EM>check</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  58            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>char</EM><STRONG>_</STRONG><EM>check</EM><STRONG>)(int,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*));</STRONG>
  59        <STRONG>int</STRONG> <STRONG>free_fieldtype(FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>);</STRONG>
  60
  61        <STRONG>int</STRONG> <STRONG>set_fieldtype_arg(</STRONG>
  62            <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>,</STRONG>
  63            <STRONG>void</STRONG> <STRONG>*(*</STRONG> <STRONG>const</STRONG> <EM>make</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(va_list</STRONG> <STRONG>*),</STRONG>
  64            <STRONG>void</STRONG> <STRONG>*(*</STRONG> <STRONG>const</STRONG> <EM>copy</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  65            <STRONG>void</STRONG>  <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>free</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(void</STRONG> <STRONG>*));</STRONG>
  66        <STRONG>int</STRONG> <STRONG>set_fieldtype_choice(</STRONG>
  67            <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>,</STRONG>
  68            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>next</EM><STRONG>_</STRONG><EM>choice</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  69            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>prev</EM><STRONG>_</STRONG><EM>choice</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*));</STRONG>
  70
  71        <STRONG>FIELDTYPE</STRONG> <STRONG>*link_fieldtype(FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>type1</EM><STRONG>,</STRONG>
  72                                  <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>type2</EM><STRONG>);</STRONG>
  73
  74
  75 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
  76
  77 </PRE><H3><a name="h3-new_fieldtype">new_fieldtype</a></H3><PRE>
  78        The  function  <STRONG>new_fieldtype</STRONG>  creates  a new field type usable for data
  79        validation.  Its parameters are function pointers:
  80
  81        <EM>field</EM><STRONG>_</STRONG><EM>check</EM>
  82             This function checks  the  validity  of  an  entered  data  string
  83             whenever  the  user  attempts  to  leave  a  field.   It  has  two
  84             arguments:
  85
  86             <STRONG>o</STRONG>   The  (FIELD  *)  argument  is  passed  in  so  the  validation
  87                 predicate   can  see  the  field's  buffer,  sizes  and  other
  88                 attributes.
  89
  90             <STRONG>o</STRONG>   The second argument  is  an  argument-block  structure,  about
  91                 which more below.
  92
  93        <EM>char</EM><STRONG>_</STRONG><EM>check</EM>
  94             This function validates input characters as they are entered.  The
  95             form library passes it the character to be checked and  a  pointer
  96             to an argument-block structure.
  97
  98
  99 </PRE><H3><a name="h3-free_fieldtype">free_fieldtype</a></H3><PRE>
 100        The  <STRONG>free_fieldtype</STRONG>  function  frees  the  space  allocated for a given
 101        validation type by <STRONG>new_fieldtype</STRONG>.
 102
 103
 104 </PRE><H3><a name="h3-set_fieldtype_arg">set_fieldtype_arg</a></H3><PRE>
 105        The  function  <STRONG>set_fieldtype_arg</STRONG>  associates  three  storage-management
 106        functions with a field type:
 107
 108        <EM>make</EM><STRONG>_</STRONG><EM>arg</EM>
 109             This  function  is  automatically applied to the list of arguments
 110             you give <STRONG>set_field_type</STRONG> when attaching validation to a field.   It
 111             stores  the  arguments in an allocated argument-block object which
 112             is used when validating input.
 113
 114        <EM>copy</EM><STRONG>_</STRONG><EM>arg</EM>
 115             This function may be used by applications to copy argument-blocks.
 116
 117        <EM>free</EM><STRONG>_</STRONG><EM>arg</EM>
 118             Frees an argument-block structure.
 119
 120        You must supply the <EM>make</EM><STRONG>_</STRONG><EM>arg</EM> function.  The other two are optional: you
 121        may  supply NULL for them.  In this case, the form library assumes that
 122        <EM>make</EM><STRONG>_</STRONG><EM>arg</EM> does not allocate memory but simply loads the argument into  a
 123        single scalar value.
 124
 125
 126 </PRE><H3><a name="h3-set_fieldtype_choice">set_fieldtype_choice</a></H3><PRE>
 127        The  form  driver  requests  <STRONG>REQ_NEXT_CHOICE</STRONG> and <STRONG>REQ_PREV_CHOICE</STRONG> assume
 128        that the possible values of a field form an ordered  set,  and  provide
 129        the forms user with a way to move through the set.
 130
 131        The  <STRONG>set_fieldtype_choice</STRONG>  function  allows forms programmers to define
 132        successor  and  predecessor  functions  for  the  field  type.    These
 133        functions  take  the  field  pointer and an argument-block structure as
 134        arguments.
 135
 136
 137 </PRE><H3><a name="h3-link_fieldtype">link_fieldtype</a></H3><PRE>
 138        The function <STRONG>link_fieldtype</STRONG> creates a new field type from the two given
 139        types.  They are connected by an logical 'OR'.
 140
 141
 142 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
 143        The  pointer-valued  routines  return  NULL  on  error.  They set <STRONG>errno</STRONG>
 144        according to their success:
 145
 146        <STRONG>E_OK</STRONG> The routine succeeded.
 147
 148        <STRONG>E_BAD_ARGUMENT</STRONG>
 149             Routine detected an incorrect or out-of-range argument.
 150
 151        <STRONG>E_SYSTEM_ERROR</STRONG>
 152             System error occurred, e.g., malloc failure.
 153
 154        The integer-valued routines return one of the following codes on error:
 155
 156        <STRONG>E_OK</STRONG> The routine succeeded.
 157
 158        <STRONG>E_BAD_ARGUMENT</STRONG>
 159             Routine detected an incorrect or out-of-range argument.
 160
 161        <STRONG>E_CONNECTED</STRONG>
 162             The field is already connected to a form.
 163
 164        <STRONG>E_CURRENT</STRONG>
 165             The field is the current field.
 166
 167        <STRONG>E_SYSTEM_ERROR</STRONG>
 168             System error occurred (see <STRONG>errno(3)</STRONG>).
 169
 170
 171 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
 172        These routines emulate the System  V  forms  library.   They  were  not
 173        supported on Version 7 or BSD versions.
 174
 175
 176 </PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
 177        Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
 178        Raymond.
 179
 180
 181 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
 182        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>, <STRONG><A HREF="form_field_validation.3x.html">form_field_validation(3x)</A></STRONG>
 183
 184
 185
 186 ncurses 6.5                       2024-03-16                <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
 187 </PRE>
 188 <div class="nav">
 189 <ul>
 190 <li><a href="#h2-NAME">NAME</a></li>
 191 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
 192 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
 193 <ul>
 194 <li><a href="#h3-new_fieldtype">new_fieldtype</a></li>
 195 <li><a href="#h3-free_fieldtype">free_fieldtype</a></li>
 196 <li><a href="#h3-set_fieldtype_arg">set_fieldtype_arg</a></li>
 197 <li><a href="#h3-set_fieldtype_choice">set_fieldtype_choice</a></li>
 198 <li><a href="#h3-link_fieldtype">link_fieldtype</a></li>
 199 </ul>
 200 </li>
 201 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
 202 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
 203 <li><a href="#h2-AUTHORS">AUTHORS</a></li>
 204 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
 205 </ul>
 206 </div>
 207 </BODY>
 208 </HTML>