ncurses 6.1 - patch 20190727

[ncurses.git] / man / form_driver.3x

diff --git a/man/form_driver.3x b/man/form_driver.3x
index 4084eac08aaf5dded19ed599a0fe41ddddc2fc25..3b8308a927485820b2be7c015b4f6a5d2f97481e 100644 (file)
--- a/man/form_driver.3x
+++ b/man/form_driver.3x
@@ -1,5 +1,5 @@
 .\"***************************************************************************
-.\" Copyright (c) 1998-2010,2015 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            *
@@ -26,13 +26,15 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: form_driver.3x,v 1.24 2015/08/02 18:21:11 tom Exp $
+.\" $Id: form_driver.3x,v 1.32 2019/01/20 20:31:42 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 \- command-processing loop of the form system
+\fBform_driver\fR,
+\fBform_driver_w\fR \- command-processing loop of the form system
 .SH SYNOPSIS
 \fB#include <form.h>\fR
 .br
@@ -47,7 +49,8 @@ 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
@@ -67,7 +70,7 @@ 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.
@@ -131,8 +134,37 @@ 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
@@ -178,7 +210,8 @@ 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
@@ -205,11 +238,14 @@ 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.
@@ -217,14 +253,18 @@ The form driver code saw an unknown request code.
 .SH SEE ALSO
 \fBcurses\fR(3X),
 \fBform\fR(3X),
+\fBform_field_buffer\fR(3X),
+\fBform_field_validation\fR(3X),
+\fBform_fieldtype\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.