'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998,2000,2001 Free Software Foundation, Inc. *
+.\" Copyright (c) 1998-2018,2019 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: form_fieldtype.3x,v 1.9 2001/08/04 20:36:25 William.Setzer Exp $
+.\" $Id: form_fieldtype.3x,v 1.19 2019/01/20 20:31:42 tom Exp $
.TH form_fieldtype 3X ""
.SH NAME
-\fBform_fieldtype\fR - define validation-field types
+\fBform_fieldtype\fR \- define validation-field types
.SH SYNOPSIS
\fB#include <form.h>\fR
.br
.br
.SH DESCRIPTION
The function \fBnew_fieldtype\fR creates a new field type usable for data
-validation. You supply it with \fIfield_check\fR, a predicate to check the
-validity of an entered data string whenever the user attempt to leave a field.
+validation.
+You supply it with \fIfield_check\fR, 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 predicate can see the
field's buffer, sizes and other attributes; the second argument is an
argument-block structure, about which more below.
-
+.PP
You also supply \fBnew_fieldtype\fR with \fIchar_check\fR,
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.
-
+.PP
The function \fBfree_fieldtype\fR frees the space allocated for a given
validation type.
-
-The function \fBset_fieldtype\fR associates three storage-management functions
-with a field type. The \fImak_arg\fR function is automatically applied to the
+.PP
+The function \fBset_fieldtype_arg\fR associates
+three storage-management functions with a field type.
+The \fImake_arg\fR function is automatically applied to the
list of arguments you give \fBset_field_type\fR 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 predicated. 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 \fImak_arg\fR function,
-the other two are optional, you may supply NULL for them. In this case it
-is assumed, that \fImak_arg\fR doesn't allocate memory but simply loads the
+object which can later be passed to validation predicated.
+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 \fImake_arg\fR function,
+the other two are optional, you may supply NULL for them.
+In this case it is assumed
+that \fImake_arg\fR does not allocate memory but simply loads the
argument into a single scalar value.
-
+.PP
+The function \fBlink_fieldtype\fR creates
+a new field type from the two given types.
+They are connected by an logical 'OR'.
+.PP
The form driver requests \fBREQ_NEXT_CHOICE\fR and \fBREQ_PREV_CHOICE\fR 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 \fBset_fieldtype_choice\fR
+user with a way to move through the set.
+The \fBset_fieldtype_choice\fR
function allows forms programmers to define successor and predecessor functions
-for the field type. These functions take the field pointer and an
+for the field type.
+These functions take the field pointer and an
argument-block structure as arguments.
.SH RETURN VALUE
The pointer-valued routines return NULL on error.
-
+They set errno according to their success:
+.TP 5
+.B E_OK
+The routine succeeded.
+.TP 5
+.B E_BAD_ARGUMENT
+Routine detected an incorrect or out-of-range argument.
+.TP 5
+.B E_SYSTEM_ERROR
+System error occurred, e.g., malloc failure.
+.PP
The integer-valued routines return one of the following codes on
error:
.TP 5
-\fBE_OK\fR
+.B E_OK
The routine succeeded.
.TP 5
-\fBE_SYSTEM_ERROR\fR
-System error occurred (see \fBerrno\fR).
-.TP 5
-\fBE_BAD_ARGUMENT\fR
+.B E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
.TP 5
-\fBE_CONNECTED\fR
+.B E_CONNECTED
The field is already connected to a form.
+.TP 5
+.B E_CURRENT
+The field is the current field.
+.TP 5
+.B E_SYSTEM_ERROR
+System error occurred (see \fBerrno\fR(3)).
.SH SEE ALSO
\fBcurses\fR(3X), \fBform\fR(3X).
.SH NOTES
The header file \fB<form.h>\fR automatically includes the header file
\fB<curses.h>\fR.
-
+.PP
All of the \fB(char *)\fR arguments of these functions should actually be
\fB(void *)\fR. The type has been left uncorrected for strict compatibility
with System V.
.SH PORTABILITY
-These routines emulate the System V forms library. They were not supported on
+These routines emulate the System V forms library.
+They were not supported on
Version 7 or BSD versions.
.SH AUTHORS
-Juergen Pfeifer. Manual pages and adaptation for new curses by Eric
-S. Raymond.
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+Juergen Pfeifer.
+Manual pages and adaptation for new curses by Eric S. Raymond.
projects / ncurses.git / blobdiff