'\" t
-.TH form_field 3X ""
+.\"***************************************************************************
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 1998-2006,2010 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 *
+.\" "Software"), to deal in the Software without restriction, including *
+.\" without limitation the rights to use, copy, modify, merge, publish, *
+.\" distribute, distribute with modifications, sublicense, and/or sell *
+.\" copies of the Software, and to permit persons to whom the Software is *
+.\" furnished to do so, subject to the following conditions: *
+.\" *
+.\" The above copyright notice and this permission notice shall be included *
+.\" in all copies or substantial portions of the Software. *
+.\" *
+.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+.\" *
+.\" Except as contained in this notice, the name(s) of the above copyright *
+.\" holders shall not be used in advertising or otherwise to promote the *
+.\" sale, use or other dealings in this Software without prior written *
+.\" authorization. *
+.\"***************************************************************************
+.\"
+.\" $Id: form_fieldtype.3x,v 1.28 2020/12/12 17:11:21 tom Exp $
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
+.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
+.sp
+\fBFIELDTYPE *new_fieldtype(\fP
+ \fBbool (* const \fP\fIfield_check\fP\fB)(FIELD *, const void *),\fP
+ \fBbool (* const \fP\fIchar_check\fP\fB)(int, const void *));\fP
.br
-FIELDTYPE *new_fieldtype(
- bool (* const field_check)(FIELD *, const void *),
- bool (* const char_check)(int, const void *));
+\fBint free_fieldtype(FIELDTYPE *\fP\fIfieldtype\fP\fB);\fP
+.sp
+\fBint set_fieldtype_arg(\fP
+ \fBFIELDTYPE *\fP\fIfieldtype\fP\fB,\fP
+ \fBvoid *(* const \fP\fImake_arg\fP\fB)(va_list *),\fP
+ \fBvoid *(* const \fP\fIcopy_arg\fP\fB)(const void *),\fP
+ \fBvoid (* const \fP\fIfree_arg\fP\fB)(void *));\fP
.br
-int free_fieldtype(FIELDTYPE *fieldtype);
-.br
-int set_fieldtype_arg(
- FIELDTYPE *fieldtype,
- void *(* const make_arg)(va_list *),
- void *(* const copy_arg)(const void *),
- void (* const free_arg)(void *));
-.br
-int set_fieldtype_choice(
- FIELDTYPE *fieldtype
- bool (* const next_choice)(FIELD *, const void *),
- bool (* const prev_choice)(FIELD *, const void *));
-.br
-FIELDTYPE *link_fieldtype(FIELDTYPE *type1,
- FIELDTYPE *type2);
-.br
+\fBint set_fieldtype_choice(\fP
+ \fBFIELDTYPE *\fP\fIfieldtype\fP\fB,\fP
+ \fBbool (* const \fP\fInext_choice\fP\fB)(FIELD *, const void *),\fP
+ \fBbool (* const \fP\fIprev_choice\fP\fB)(FIELD *, const void *));\fP
+.sp
+\fBFIELDTYPE *link_fieldtype(FIELDTYPE *\fP\fItype1\fP\fB,\fP
+ \fBFIELDTYPE *\fP\fItype2\fP\fB);\fP
.SH DESCRIPTION
+.SS new_fieldtype
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.
+Its parameters are function pointers:
+.TP 5
+\fIfield_check\fR
+This function checks the
+validity of an entered data string whenever the user attempts to leave a field.
+It has two arguments:
+.RS
+.bP
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
+field's buffer, sizes and other attributes.
+.bP
+The second argument is an
argument-block structure, about which more below.
-
-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.
-
-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
+.RE
+.TP 5
+\fIchar_check\fR
+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.
+.SS free_fieldtype
+.PP
+The \fBfree_fieldtype\fR function
+frees the space allocated for a given validation type by \fBnew_fieldtype\fP.
+.SS set_fieldtype_arg
+.PP
+The function \fBset_fieldtype_arg\fR associates
+three storage-management functions with a field type:
+.TP 5
+\fImake_arg\fR
+This 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.
-
+to a field.
+It stores the arguments in an allocated argument-block
+object which is used when validating input.
+.TP 5
+\fIcopy_arg\fR
+This function may be used by applications to copy argument-blocks.
+.TP 5
+\fIfree_arg\fR
+Frees an argument-block structure.
+.PP
+You must supply the \fImake_arg\fR function.
+The other two are optional: you may supply NULL for them.
+In this case, the form library assumes
+that \fImake_arg\fR does not allocate memory but simply loads the
+argument into a single scalar value.
+.SS set_fieldtype_choice
+.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.
+.PP
+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.
+.SS link_fieldtype
+.PP
+The function \fBlink_fieldtype\fR creates
+a new field type from the two given types.
+They are connected by an logical 'OR'.
.SH RETURN VALUE
The pointer-valued routines return NULL on error.
-
+They set \fBerrno\fP 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).
+\fBcurses\fR(3X),
+\fBform\fR(3X),
+\fBform_field_validation\fR(3X).
.SH NOTES
The header file \fB<form.h>\fR automatically includes the header file
\fB<curses.h>\fR.
-
-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