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- * @Id: form_fieldtype.3x,v 1.21 2020/03/28 19:06:28 tom Exp @
+ * @Id: form_fieldtype.3x,v 1.28 2020/12/12 17:11:21 tom Exp @
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+<TITLE>form_fieldtype 3X</TITLE>
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-<H1 class="no-header">form_fieldtype 3x</H1>
+<H1 class="no-header">form_fieldtype 3X</H1>
<PRE>
-<STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG> <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
+<B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B> <B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
- <STRONG>form_fieldtype</STRONG> - define validation-field types
+ <B>form_fieldtype</B> - define validation-field types
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></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);
+ <B>#include</B> <B><form.h></B>
+
+ <B>FIELDTYPE</B> <B>*new_fieldtype(</B>
+ <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>
+ <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>
+ <B>int</B> <B>free_fieldtype(FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>);</B>
+
+ <B>int</B> <B>set_fieldtype_arg(</B>
+ <B>FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>,</B>
+ <B>void</B> <B>*(*</B> <B>const</B> <I>make</I><B>_</B><I>arg</I><B>)(va_list</B> <B>*),</B>
+ <B>void</B> <B>*(*</B> <B>const</B> <I>copy</I><B>_</B><I>arg</I><B>)(const</B> <B>void</B> <B>*),</B>
+ <B>void</B> <B>(*</B> <B>const</B> <I>free</I><B>_</B><I>arg</I><B>)(void</B> <B>*));</B>
+ <B>int</B> <B>set_fieldtype_choice(</B>
+ <B>FIELDTYPE</B> <B>*</B><I>fieldtype</I><B>,</B>
+ <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>
+ <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>
+
+ <B>FIELDTYPE</B> <B>*link_fieldtype(FIELDTYPE</B> <B>*</B><I>type1</I><B>,</B>
+ <B>FIELDTYPE</B> <B>*</B><I>type2</I><B>);</B>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></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 attempts to leave
- a field. The (FIELD *) argument is passed in so the validation predi-
- cate 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 vali-
- dation type.
-
- The function <STRONG>set_fieldtype_arg</STRONG> associates three storage-management
- functions with a field type. The <EM>make</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 predi-
- cated. 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 <EM>make</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>make</EM><STRONG>_</STRONG><EM>arg</EM> does
- not allocate memory but simply loads the argument into a single scalar
- value.
-
- The function <STRONG>link_fieldtype</STRONG> creates a new field type from the two given
- types. They are connected by an logical 'OR'.
- 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_field-</STRONG>
- <STRONG>type_choice</STRONG> 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.
+</PRE><H3><a name="h3-new_fieldtype">new_fieldtype</a></H3><PRE>
+ The function <B>new_fieldtype</B> creates a new field type usable for data
+ validation. Its parameters are function pointers:
+
+ <I>field</I><B>_</B><I>check</I>
+ This function checks the validity of an entered data string
+ whenever the user attempts to leave a field. It has two
+ arguments:
+
+ <B>o</B> The (FIELD *) argument is passed in so the validation
+ predicate can see the field's buffer, sizes and other
+ attributes.
+
+ <B>o</B> The second argument is an argument-block structure, about
+ which more below.
+
+ <I>char</I><B>_</B><I>check</I>
+ This function validates input characters as they are entered. The
+ form library passes it the character to be checked and a pointer
+ to an argument-block structure.
+
+
+</PRE><H3><a name="h3-free_fieldtype">free_fieldtype</a></H3><PRE>
+ The <B>free_fieldtype</B> function frees the space allocated for a given
+ validation type by <B>new_fieldtype</B>.
+
+
+</PRE><H3><a name="h3-set_fieldtype_arg">set_fieldtype_arg</a></H3><PRE>
+ The function <B>set_fieldtype_arg</B> associates three storage-management
+ functions with a field type:
+
+ <I>make</I><B>_</B><I>arg</I>
+ This function is automatically applied to the list of arguments
+ you give <B>set_field_type</B> when attaching validation to a field. It
+ stores the arguments in an allocated argument-block object which
+ is used when validating input.
+
+ <I>copy</I><B>_</B><I>arg</I>
+ This function may be used by applications to copy argument-blocks.
+
+ <I>free</I><B>_</B><I>arg</I>
+ Frees an argument-block structure.
+
+ You must supply the <I>make</I><B>_</B><I>arg</I> function. The other two are optional: you
+ may supply NULL for them. In this case, the form library assumes that
+ <I>make</I><B>_</B><I>arg</I> does not allocate memory but simply loads the argument into a
+ single scalar value.
+
+
+</PRE><H3><a name="h3-set_fieldtype_choice">set_fieldtype_choice</a></H3><PRE>
+ The form driver requests <B>REQ_NEXT_CHOICE</B> and <B>REQ_PREV_CHOICE</B> 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 <B>set_fieldtype_choice</B> 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.
+
+
+</PRE><H3><a name="h3-link_fieldtype">link_fieldtype</a></H3><PRE>
+ The function <B>link_fieldtype</B> creates a new field type from the two given
+ types. They are connected by an logical 'OR'.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- The pointer-valued routines return NULL on error. They set <STRONG>errno</STRONG>
+ The pointer-valued routines return NULL on error. They set <B>errno</B>
according to their success:
- <STRONG>E_OK</STRONG> The routine succeeded.
+ <B>E_OK</B> The routine succeeded.
- <STRONG>E_BAD_ARGUMENT</STRONG>
+ <B>E_BAD_ARGUMENT</B>
Routine detected an incorrect or out-of-range argument.
- <STRONG>E_SYSTEM_ERROR</STRONG>
+ <B>E_SYSTEM_ERROR</B>
System error occurred, e.g., malloc failure.
The integer-valued routines return one of the following codes on error:
- <STRONG>E_OK</STRONG> The routine succeeded.
+ <B>E_OK</B> The routine succeeded.
- <STRONG>E_BAD_ARGUMENT</STRONG>
+ <B>E_BAD_ARGUMENT</B>
Routine detected an incorrect or out-of-range argument.
- <STRONG>E_CONNECTED</STRONG>
+ <B>E_CONNECTED</B>
The field is already connected to a form.
- <STRONG>E_CURRENT</STRONG>
+ <B>E_CURRENT</B>
The field is the current field.
- <STRONG>E_SYSTEM_ERROR</STRONG>
- System error occurred (see <STRONG>errno(3)</STRONG>).
+ <B>E_SYSTEM_ERROR</B>
+ System error occurred (see <B>errno(3)</B>).
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
- <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>.
+ <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>.
</PRE><H2><a name="h2-NOTES">NOTES</a></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.
+ The header file <B><form.h></B> automatically includes the header file
+ <B><curses.h></B>.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- These routines emulate the System V forms library. They were not sup-
- ported on Version 7 or BSD versions.
+ These routines emulate the System V forms library. They were not
+ supported on Version 7 or BSD versions.
</PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
- <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
+ <B><A HREF="form_fieldtype.3X.html">form_fieldtype(3X)</A></B>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
-<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
+<ul>
+<li><a href="#h3-new_fieldtype">new_fieldtype</a></li>
+<li><a href="#h3-free_fieldtype">free_fieldtype</a></li>
+<li><a href="#h3-set_fieldtype_arg">set_fieldtype_arg</a></li>
+<li><a href="#h3-set_fieldtype_choice">set_fieldtype_choice</a></li>
+<li><a href="#h3-link_fieldtype">link_fieldtype</a></li>
+</ul>
+</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
<li><a href="#h2-NOTES">NOTES</a></li>