NAME

form_fieldtype: new_fieldtype, free_fieldtype, set_fieldtype_arg, set_fieldtype_choice, link_fieldtype − forms fieldtype routines

SYNOPSIS

#include <form.h>
FIELDTYPE ∗new_fieldtype(int (∗ field_check)(FIELD ∗, char ∗),
int (∗ char_check)(int, char ∗));
int free_fieldtype(FIELDTYPE ∗fieldtype);
int set_fieldtype_arg(FIELDTYPE ∗fieldtype,
char ∗(∗ mak_arg)(va_list ∗),
char ∗(∗ copy_arg)(char ∗), void (∗ free_arg)(char ∗));
int set_fieldtype_choice(FIELDTYPE ∗fieldtype,
int (∗ next_choice)(FIELD ∗, char ∗),
int (∗ prev_choice)(FIELD ∗, char ∗));
FIELDTYPE ∗link_fieldtype(FIELDTYPE ∗type1, FIELDTYPE ∗type2);

DESCRIPTION

new_fieldtype creates a new field type.  The application programmer must write the function field_check, which validates the field value, and the function char_check, which validates each character.  free_fieldtype frees the space allocated for the field type. 

By associating function pointers with a field type, set_fieldtype_arg connects to the field type additional arguments necessary for a set_field_type call.  Function mak_arg allocates a structure for the field specific parameters to set_field_type and returns a pointer to the saved data.  Function copy_arg duplicates the structure created by make_arg.  Function free_arg frees any storage allocated by make_arg or copy_arg. 

The form_driver requests REQ_NEXT_CHOICE and REQ_PREV_CHOICE let the user request the next or previous value of a field type comprising an ordered set of values.  set_fieldtype_choice allows the application programmer to implement these requests for the given field type.  It associates with the given field type those application-defined functions that return pointers to the next or previous choice for the field. 

link_fieldtype returns a pointer to the field type built from the two given types.  The constituent types may be any application-defined or pre-defined types. 

RETURN VALUE

Routines that return pointers always return NULL on error.  Routines that return an integer return one of the following:

NOTES

The header file form.h automatically includes the header files eti.h and curses.h. 

SEE ALSO

curses(3X), forms(3X)