FORMS(3)

NAME
free_fieldtype, link_fieldtype, new_fieldtype, set_fieldtype_arg, set_fieldtype_choice - form library

LIBRARY
libform

SYNOPSIS
#include <form.h>
int
free_fieldtype(FIELDTYPE *fieldtype);
FIELDTYPE *
link_fieldtype(FIELDTYPE *type1, FIELDTYPE *type2);
FIELDTYPE *
new_fieldtype(int (*field_check)(FIELD *, char *), int (*char_check)(int, char *));
int
set_fieldtype_arg(FIELDTYPE *fieldtype, char * (*make_args)(va_list *), char * (*copy_args)(char *), void (*free_args)(char *));
int
set_fieldtype_choice(FIELDTYPE *fieldtype, int (*next_choice)(FIELD *, char *), int (*prev_choice)(FIELD *, char *));

DESCRIPTION
The function free_fieldtype() frees the storage associated with the field type and destroys it. The function link_fieldtype() links together the two given field types to produce a new field type. A new field type can be created by calling new_fieldtype() which requires pointers to two functions which perform validation, the field_check function must validate the field contents and return TRUE if they are acceptable and FALSE if they are not. The char_check validates the character input into the field, this function will be called for each character entered, if the character can be entered into the field then char_check must return TRUE. Neither field_check nor char_check may be NULL. The functions for handling the field type arguments can be defined by using the set_fieldtype_arg() function, the make_args function is used to create new arguments for the fieldtype, the copy_args is used to copy the fieldtype arguments to a new arguments structure and free_args is used to destroy the fieldtype arguments and release any associated storage, none of these function pointers may be NULL. The field type choice functions can be set by calling set_fieldtype_choice(), the next_choice and prev_choice specify the next and previous choice functions for the field type. These functions must perform the necessary actions to select the next or previous choice for the field, updating the field buffer if necessary. The choice functions must return TRUE if the function succeeded and FALSE otherwise.

RETURN VALUES
Functions returning pointers will return NULL if an error is detected. The functions that return an int will return one of the following error values:

E_OK
    The function was successful.
E_BAD_ARGUMENT
    The function was passed a bad argument.
E_CONNECTED
    The field is connected to a form.

SEE ALSO
curses(3), forms(3)

NOTES
The header <form.h> automatically includes both <curses.h> and <eti.h>.