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| <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> |
| |
| |
| |
| |
| </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE> |
| <STRONG>form_fieldtype</STRONG> - 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); |
| |
| |
| </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><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE> |
| The pointer-valued routines return NULL on error. They set errno |
| according to their success: |
| |
| <STRONG>E_OK</STRONG> The routine succeeded. |
| |
| <STRONG>E_BAD_ARGUMENT</STRONG> |
| Routine detected an incorrect or out-of-range argument. |
| |
| <STRONG>E_SYSTEM_ERROR</STRONG> |
| 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. |
| |
| <STRONG>E_BAD_ARGUMENT</STRONG> |
| Routine detected an incorrect or out-of-range argument. |
| |
| <STRONG>E_CONNECTED</STRONG> |
| The field is already connected to a form. |
| |
| <STRONG>E_CURRENT</STRONG> |
| The field is the current field. |
| |
| <STRONG>E_SYSTEM_ERROR</STRONG> |
| System error occurred (see <STRONG>errno(3)</STRONG>). |
| |
| |
| </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>. |
| |
| |
| </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. |
| |
| |
| </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. |
| |
| |
| </PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE> |
| Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. |
| Raymond. |
| |
| |
| |
| <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG> |
| </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-RETURN-VALUE">RETURN VALUE</a></li> |
| <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> |
| <li><a href="#h2-NOTES">NOTES</a></li> |
| <li><a href="#h2-PORTABILITY">PORTABILITY</a></li> |
| <li><a href="#h2-AUTHORS">AUTHORS</a></li> |
| </ul> |
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