X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fform_driver.3x;h=9c096f90d4c5898853f00bd3a83c989c103dff24;hp=73245851410513a944ea4902eaa7863ee100bf99;hb=152c5a605234b7ea36ba3a03ec07e124bb6aac75;hpb=b11cef1e315b58820ea0cde239ebf2f741ef8948

diff --git a/man/form_driver.3x b/man/form_driver.3x
index 73245851..9c096f90 100644
--- a/man/form_driver.3x
+++ b/man/form_driver.3x
@@ -1,5 +1,6 @@
 .\"***************************************************************************
-.\" Copyright (c) 1998-2010,2015 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey                                *
+.\" Copyright 1998-2016,2017 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            *
@@ -26,17 +27,18 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: form_driver.3x,v 1.25 2015/12/05 21:06:26 tom Exp $
+.\" $Id: form_driver.3x,v 1.35 2020/12/19 21:34:15 tom Exp $
 .TH form_driver 3X ""
 .de bP
-.IP \(bu 4
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
 ..
 .SH NAME
 \fBform_driver\fR,
 \fBform_driver_w\fR \- command-processing loop of the form system
 .SH SYNOPSIS
 \fB#include <form.h>\fR
-.br
+.sp
 \fBint form_driver(FORM *\fP\fIform\fP\fB, int \fP\fIc\fP\fB);\fP
 .br
 \fBint form_driver_w(FORM *\fP\fIform\fP\fB, int \fP\fIc\fP\fB, wchar_t \fP\fIwch\fP\fB);\fP
@@ -48,7 +50,8 @@ through \fBform_driver\fR.  This routine has three major input cases:
 .bP
 The input is a form navigation request.
 Navigation request codes are constants defined in \fB<form.h>\fP,
-which are distinct from the key- and character codes returned by \fBwgetch\fP(3X).
+which are distinct from the key- and character codes returned
+by \fBwgetch\fP(3X).
 .bP
 The input is a printable character.
 Printable characters (which must be positive, less than 256) are
@@ -68,7 +71,7 @@ is a wide character or a request.
 The form driver requests are as follows:
 .TS
 l l
-_ _ _
+_ _
 l l.
 \fIName\fR	\fIDescription\fR
 REQ_BEG_FIELD	Move to the beginning of the field.
@@ -132,8 +135,37 @@ REQ_VALIDATION	Validate field.
 .TE
 .PP
 If the second argument is a printable character, the driver places it
-in the current position in the current field.  If it is one of the forms
+in the current position in the current field.
+If it is one of the forms
 requests listed above, that request is executed.
+.SS Field validation
+The form library makes updates to the window associated
+with form fields rather than directly to the field buffers.
+.PP
+The form driver provides low-level control over updates to the form fields.
+The form driver also provides for validating modified fields
+to ensure that the contents
+meet whatever constraints an application may attach using \fBset_field_type\fP.
+.PP
+.PP
+You can validate a field without making any changes to it using
+\fBREQ_VALIDATION\fP.
+The form driver also validates a field in these cases:
+.bP
+a call to \fBset_current_field\fP attempts to move to a different field.
+.bP
+a call to \fBset_current_page\fP attempts to move
+to a different page of the form.
+.bP
+a request attempts to move to a different field.
+.bP
+a request attempts to move to a different page of the form.
+.PP
+In each case, the move fails if the field is invalid.
+.PP
+If the modified field is valid, the form driver copies the modified
+data from the window associated with the field
+to the field buffer.
 .SS Mouse handling
 .PP
 If the second argument is the KEY_MOUSE special key, the associated
@@ -179,7 +211,8 @@ If a translation
 into a request was done, \fBform_driver\fR returns the result of this request.
 .RE
 .PP
-If you clicked outside the user window or the mouse event could not be translated
+If you clicked outside the user window
+or the mouse event could not be translated
 into a form request an \fBE_REQUEST_DENIED\fR is returned.
 .SS Application-defined commands
 .PP
@@ -206,11 +239,14 @@ The form has not been posted.
 .B E_INVALID_FIELD
 Contents of field is invalid.
 .TP 5
+.B E_NOT_CONNECTED
+No fields are connected to the form.
+.TP 5
 .B E_REQUEST_DENIED
 The form driver could not process the request.
 .TP 5
 .B E_SYSTEM_ERROR
-System error occurred (see \fBerrno\fR).
+System error occurred (see \fBerrno\fR(3)).
 .TP 5
 .B E_UNKNOWN_COMMAND
 The form driver code saw an unknown request code.
@@ -218,14 +254,18 @@ The form driver code saw an unknown request code.
 .SH SEE ALSO
 \fBcurses\fR(3X),
 \fBform\fR(3X),
+\fBform_fieldtype\fR(3X),
+\fBform_field_buffer\fR(3X),
+\fBform_field_validation\fR(3X),
 \fBform_variables\fR(3X),
 \fBgetch\fR(3X).
 .SH NOTES
 The header file \fB<form.h>\fR automatically includes the header files
 \fB<curses.h>\fR.
 .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.
+Juergen Pfeifer.
+Manual pages and adaptation for new curses by Eric S. Raymond.