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31 * @Id: form_fieldtype.3x,v 1.28 2020/12/12 17:11:21 tom Exp @
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43 <H1 class="no-header">form_fieldtype 3X</H1>
45 <B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B> <B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B>
50 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
51 <B>form_fieldtype</B> - define validation-field types
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <B>#include</B> <B><form.h></B>
57 <B>FIELDTYPE</B> <B>*new_fieldtype(</B>
58 <B>bool</B> <B>(*</B> <B>const</B> <I>field</I><B>_</B><I>check</I><B>)(FIELD</B> <B>*,</B> <B>const</B> <B>void</B> <B>*),</B>
59 <B>bool</B> <B>(*</B> <B>const</B> <I>char</I><B>_</B><I>check</I><B>)(int,</B> <B>const</B> <B>void</B> <B>*));</B>
60 <B>int</B> <B>free_fieldtype(FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>);</B>
62 <B>int</B> <B>set_fieldtype_arg(</B>
63 <B>FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>,</B>
64 <B>void</B> <B>*(*</B> <B>const</B> <I>make</I><B>_</B><I>arg</I><B>)(va_list</B> <B>*),</B>
65 <B>void</B> <B>*(*</B> <B>const</B> <I>copy</I><B>_</B><I>arg</I><B>)(const</B> <B>void</B> <B>*),</B>
66 <B>void</B> <B>(*</B> <B>const</B> <I>free</I><B>_</B><I>arg</I><B>)(void</B> <B>*));</B>
67 <B>int</B> <B>set_fieldtype_choice(</B>
68 <B>FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>,</B>
69 <B>bool</B> <B>(*</B> <B>const</B> <I>next</I><B>_</B><I>choice</I><B>)(FIELD</B> <B>*,</B> <B>const</B> <B>void</B> <B>*),</B>
70 <B>bool</B> <B>(*</B> <B>const</B> <I>prev</I><B>_</B><I>choice</I><B>)(FIELD</B> <B>*,</B> <B>const</B> <B>void</B> <B>*));</B>
72 <B>FIELDTYPE</B> <B>*link_fieldtype(FIELDTYPE</B> <B>*</B><I>type1</I><B>,</B>
73 <B>FIELDTYPE</B> <B>*</B><I>type2</I><B>);</B>
76 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
78 </PRE><H3><a name="h3-new_fieldtype">new_fieldtype</a></H3><PRE>
79 The function <B>new_fieldtype</B> creates a new field type usable for data
80 validation. Its parameters are function pointers:
82 <I>field</I><B>_</B><I>check</I>
83 This function checks the validity of an entered data string
84 whenever the user attempts to leave a field. It has two
87 <B>o</B> The (FIELD *) argument is passed in so the validation
88 predicate can see the field's buffer, sizes and other
91 <B>o</B> The second argument is an argument-block structure, about
94 <I>char</I><B>_</B><I>check</I>
95 This function validates input characters as they are entered. The
96 form library passes it the character to be checked and a pointer
97 to an argument-block structure.
100 </PRE><H3><a name="h3-free_fieldtype">free_fieldtype</a></H3><PRE>
101 The <B>free_fieldtype</B> function frees the space allocated for a given
102 validation type by <B>new_fieldtype</B>.
105 </PRE><H3><a name="h3-set_fieldtype_arg">set_fieldtype_arg</a></H3><PRE>
106 The function <B>set_fieldtype_arg</B> associates three storage-management
107 functions with a field type:
109 <I>make</I><B>_</B><I>arg</I>
110 This function is automatically applied to the list of arguments
111 you give <B>set_field_type</B> when attaching validation to a field. It
112 stores the arguments in an allocated argument-block object which
113 is used when validating input.
115 <I>copy</I><B>_</B><I>arg</I>
116 This function may be used by applications to copy argument-blocks.
118 <I>free</I><B>_</B><I>arg</I>
119 Frees an argument-block structure.
121 You must supply the <I>make</I><B>_</B><I>arg</I> function. The other two are optional: you
122 may supply NULL for them. In this case, the form library assumes that
123 <I>make</I><B>_</B><I>arg</I> does not allocate memory but simply loads the argument into a
127 </PRE><H3><a name="h3-set_fieldtype_choice">set_fieldtype_choice</a></H3><PRE>
128 The form driver requests <B>REQ_NEXT_CHOICE</B> and <B>REQ_PREV_CHOICE</B> assume
129 that the possible values of a field form an ordered set, and provide
130 the forms user with a way to move through the set.
132 The <B>set_fieldtype_choice</B> function allows forms programmers to define
133 successor and predecessor functions for the field type. These
134 functions take the field pointer and an argument-block structure as
138 </PRE><H3><a name="h3-link_fieldtype">link_fieldtype</a></H3><PRE>
139 The function <B>link_fieldtype</B> creates a new field type from the two given
140 types. They are connected by an logical 'OR'.
143 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
144 The pointer-valued routines return NULL on error. They set <B>errno</B>
145 according to their success:
147 <B>E_OK</B> The routine succeeded.
149 <B>E_BAD_ARGUMENT</B>
150 Routine detected an incorrect or out-of-range argument.
152 <B>E_SYSTEM_ERROR</B>
153 System error occurred, e.g., malloc failure.
155 The integer-valued routines return one of the following codes on error:
157 <B>E_OK</B> The routine succeeded.
159 <B>E_BAD_ARGUMENT</B>
160 Routine detected an incorrect or out-of-range argument.
163 The field is already connected to a form.
166 The field is the current field.
168 <B>E_SYSTEM_ERROR</B>
169 System error occurred (see <B>errno(3)</B>).
172 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
173 <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="form.3X.html">form(3X)</A></B>, <B><A HREF="form_field_validation.3X.html">form_field_validation(3X)</A></B>.
176 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
177 The header file <B><form.h></B> automatically includes the header file
178 <B><curses.h></B>.
181 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
182 These routines emulate the System V forms library. They were not
183 supported on Version 7 or BSD versions.
186 </PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
187 Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S.
192 <B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B>
196 <li><a href="#h2-NAME">NAME</a></li>
197 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
198 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
200 <li><a href="#h3-new_fieldtype">new_fieldtype</a></li>
201 <li><a href="#h3-free_fieldtype">free_fieldtype</a></li>
202 <li><a href="#h3-set_fieldtype_arg">set_fieldtype_arg</a></li>
203 <li><a href="#h3-set_fieldtype_choice">set_fieldtype_choice</a></li>
204 <li><a href="#h3-link_fieldtype">link_fieldtype</a></li>
207 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
208 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
209 <li><a href="#h2-NOTES">NOTES</a></li>
210 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
211 <li><a href="#h2-AUTHORS">AUTHORS</a></li>