.\"***************************************************************************
-.\" Copyright (c) 1998-2006,2007 Free Software Foundation, Inc. *
+.\" Copyright 2018-2021,2022 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: form_driver.3x,v 1.15 2007/06/02 22:56:49 tom Exp $
+.\" $Id: form_driver.3x,v 1.39 2022/02/12 20:03:40 tom Exp $
.TH form_driver 3X ""
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
.SH NAME
-\fBform_driver\fR - command-processing loop of the form system
+\fBform_driver\fP,
+\fBform_driver_w\fP \- command-processing loop of the form system
.SH SYNOPSIS
-\fB#include <form.h>\fR
+\fB#include <form.h>\fP
+.sp
+\fBint form_driver(FORM *\fIform\fB, int \fIc\fB);\fR
.br
-int form_driver(FORM *form, int c);
+\fBint form_driver_w(FORM *\fIform\fB, int \fIc\fB, wchar_t \fIwch\fB);\fR
.br
.SH DESCRIPTION
+.SS form_driver
Once a form has been posted (displayed), you should funnel input events to it
-through \fBform_driver\fR. This routine has two major input cases; either
-the input is a form navigation request or it is a printable ASCII character.
+through \fBform_driver\fP. 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).
+.bP
+The input is a printable character.
+Printable characters (which must be positive, less than 256) are
+checked according to the program's locale settings.
+.bP
+The input is the KEY_MOUSE special key associated with an mouse event.
+.SS form_driver_w
+.PP
+This extension simplifies the use of the forms library using wide characters.
+The input is either a key code (a request) or a wide character
+returned by \fBget_wch\fP(3X).
+The type must be passed as well,
+to enable the library to determine whether the parameter
+is a wide character or a request.
+.SS Form-driver requests
+.PP
The form driver requests are as follows:
-.TP 5
-REQ_NEXT_PAGE
-Move to the next page.
-.TP 5
-REQ_PREV_PAGE
-Move to the previous page.
-.TP 5
-REQ_FIRST_PAGE
-Move to the first page.
-.TP 5
-REQ_LAST_PAGE
-Move to the last field.
-.sp
-.TP 5
-REQ_NEXT_FIELD
-Move to the next field.
-.TP 5
-REQ_PREV_FIELD
-Move to the previous field.
-.TP 5
-REQ_FIRST_FIELD
-Move to the first field.
-.TP 5
-REQ_LAST_FIELD
-Move to the last field.
-.TP 5
-REQ_SNEXT_FIELD
-Move to the sorted next field.
-.TP 5
-REQ_SPREV_FIELD
-Move to the sorted previous field.
-.TP 5
-REQ_SFIRST_FIELD
-Move to the sorted first field.
-.TP 5
-REQ_SLAST_FIELD
-Move to the sorted last field.
-.TP 5
-REQ_LEFT_FIELD
-Move left to a field.
-.TP 5
-REQ_RIGHT_FIELD
-Move right to a field.
-.TP 5
-REQ_UP_FIELD
-Move up to a field.
-.TP 5
-REQ_DOWN_FIELD
-Move down to a field.
-.sp
-.TP 5
-REQ_NEXT_CHAR
-Move to the next char.
-.TP 5
-REQ_PREV_CHAR
-Move to the previous char.
-.TP 5
-REQ_NEXT_LINE
-Move to the next line.
-.TP 5
-REQ_PREV_LINE
-Move to the previous line.
-.TP 5
-REQ_NEXT_WORD
-Move to the next word.
-.TP 5
-REQ_PREV_WORD
-Move to the previous word.
-.TP 5
-REQ_BEG_FIELD
-Move to the beginning of the field.
-.TP 5
-REQ_END_FIELD
-Move to the end of the field.
-.TP 5
-REQ_BEG_LINE
-Move to the beginning of the line.
-.TP 5
-REQ_END_LINE
-Move to the end of the line.
-.TP 5
-REQ_LEFT_CHAR
-Move left in the field.
-.TP 5
-REQ_RIGHT_CHAR
-Move right in the field.
-.TP 5
-REQ_UP_CHAR
-Move up in the field.
-.TP 5
-REQ_DOWN_CHAR
-Move down in the field.
-.sp
-.TP 5
-REQ_NEW_LINE
-Insert or overlay a new line.
-.TP 5
-REQ_INS_CHAR
-Insert a blank at the cursor.
-.TP 5
-REQ_INS_LINE
-Insert a blank line at the cursor.
-.TP 5
-REQ_DEL_CHAR
-Delete character at the cursor.
-.TP 5
-REQ_DEL_PREV
-Delete character before the cursor.
-.TP 5
-REQ_DEL_LINE
-Delete line at the cursor.
-.TP 5
-REQ_DEL_WORD
-Delete blank-delimited word at the cursor.
-.TP 5
-REQ_CLR_EOL
-Clear to end of line from cursor.
-.TP 5
-REQ_CLR_EOF
-Clear to end of field from cursor.
-.TP 5
-REQ_CLR_FIELD
-Clear the entire field.
-.TP 5
-REQ_OVL_MODE
-Enter overlay mode.
-.TP 5
-REQ_INS_MODE
-Enter insert mode.
-.sp
-.TP 5
-REQ_SCR_FLINE
-Scroll the field forward a line.
-.TP 5
-REQ_SCR_BLINE
-Scroll the field backward a line.
-.TP 5
-REQ_SCR_FPAGE
-Scroll the field forward a page.
-.TP 5
-REQ_SCR_BPAGE
-Scroll the field backward a page.
-.TP 5
-REQ_SCR_FHPAGE
-Scroll the field forward half a page.
-.TP 5
-REQ_SCR_BHPAGE
-Scroll the field backward half a page.
-.sp
-.TP 5
-REQ_SCR_FCHAR
-Scroll the field forward a character.
-.TP 5
-REQ_SCR_BCHAR
-Scroll the field backward a character.
-.TP 5
-REQ_SCR_HFLINE
-Horizontal scroll the field forward a line.
-.TP 5
-REQ_SCR_HBLINE
-Horizontal scroll the field backward a line.
-.TP 5
-REQ_SCR_HFHALF
-Horizontal scroll the field forward half a line.
-.TP 5
-REQ_SCR_HBHALF
-Horizontal scroll the field backward half a line.
-.sp
-.TP
-REQ_VALIDATION
-Validate field.
-.TP
-REQ_NEXT_CHOICE
-Display next field choice.
-.TP
-REQ_PREV_CHOICE
-Display previous field choice.
+.TS
+l l
+_ _
+l l.
+\fBName\fP \fBDescription\fP
+REQ_BEG_FIELD Move to the beginning of the field.
+REQ_BEG_LINE Move to the beginning of the line.
+REQ_CLR_EOF Clear to end of field from cursor.
+REQ_CLR_EOL Clear to end of line from cursor.
+REQ_CLR_FIELD Clear the entire field.
+REQ_DEL_CHAR Delete character at the cursor.
+REQ_DEL_LINE Delete line at the cursor.
+REQ_DEL_PREV Delete character before the cursor.
+REQ_DEL_WORD Delete blank-delimited word at the cursor.
+REQ_DOWN_CHAR Move down in the field.
+REQ_DOWN_FIELD Move down to a field.
+REQ_END_FIELD Move to the end of the field.
+REQ_END_LINE Move to the end of the line.
+REQ_FIRST_FIELD Move to the first field.
+REQ_FIRST_PAGE Move to the first page.
+REQ_INS_CHAR Insert a blank at the cursor.
+REQ_INS_LINE Insert a blank line at the cursor.
+REQ_INS_MODE Enter insert mode.
+REQ_LAST_FIELD Move to the last field.
+REQ_LAST_PAGE Move to the last field.
+REQ_LEFT_CHAR Move left in the field.
+REQ_LEFT_FIELD Move left to a field.
+REQ_NEW_LINE Insert or overlay a new line.
+REQ_NEXT_CHAR Move to the next char.
+REQ_NEXT_CHOICE Display next field choice.
+REQ_NEXT_FIELD Move to the next field.
+REQ_NEXT_LINE Move to the next line.
+REQ_NEXT_PAGE Move to the next page.
+REQ_NEXT_PAGE Move to the next page.
+REQ_NEXT_WORD Move to the next word.
+REQ_OVL_MODE Enter overlay mode.
+REQ_PREV_CHAR Move to the previous char.
+REQ_PREV_CHOICE Display previous field choice.
+REQ_PREV_FIELD Move to the previous field.
+REQ_PREV_LINE Move to the previous line.
+REQ_PREV_PAGE Move to the previous page.
+REQ_PREV_WORD Move to the previous word.
+REQ_RIGHT_CHAR Move right in the field.
+REQ_RIGHT_FIELD Move right to a field.
+REQ_SCR_BCHAR Scroll the field backward a character.
+REQ_SCR_BHPAGE Scroll the field backward half a page.
+REQ_SCR_BLINE Scroll the field backward a line.
+REQ_SCR_BPAGE Scroll the field backward a page.
+REQ_SCR_FCHAR Scroll the field forward a character.
+REQ_SCR_FHPAGE Scroll the field forward half a page.
+REQ_SCR_FLINE Scroll the field forward a line.
+REQ_SCR_FPAGE Scroll the field forward a page.
+REQ_SCR_HBHALF Horizontal scroll the field backward half a line.
+REQ_SCR_HBLINE Horizontal scroll the field backward a line.
+REQ_SCR_HFHALF Horizontal scroll the field forward half a line.
+REQ_SCR_HFLINE Horizontal scroll the field forward a line.
+REQ_SFIRST_FIELD Move to the sorted first field.
+REQ_SLAST_FIELD Move to the sorted last field.
+REQ_SNEXT_FIELD Move to the sorted next field.
+REQ_SPREV_FIELD Move to the sorted previous field.
+REQ_UP_CHAR Move up in the field.
+REQ_UP_FIELD Move up to a field.
+REQ_VALIDATION Validate field.
+.TE
.PP
-If the second argument is a printable ASCII character, the driver places it
-in the current position in the current field. If it is one of the forms
+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
requests listed above, that request is executed.
-.SS MOUSE HANDLING
+.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
mouse event is translated into one of the above pre-defined requests.
-Currently only clicks in the user window (e.g. inside the form display
+Currently only clicks in the user window (e.g., inside the form display
area or the decoration window) are handled.
.PP
If you click above the display region of the form:
-.RS
+.RS 3
.TP
a REQ_PREV_FIELD is generated for a single click,
.TP
.RE
.PP
If you click below the display region of the form:
-.RS
+.RS 3
.TP
a REQ_NEXT_FIELD is generated for a single click,
.TP
.RE
.PP
If you click at an field inside the display area of the form:
-.RS
-.TP 3
--
+.RS 3
+.bP
the form cursor is positioned to that field.
-.TP 3
--
+.bP
If you double-click a field,
the form cursor is positioned to that field
-and \fBE_UNKNOWN_COMMAND\fR is returned.
+and \fBE_UNKNOWN_COMMAND\fP is returned.
This return value makes sense,
because a double click usually means that an field-specific action should
be returned.
It is exactly the purpose of this return value to signal that an
application specific command should be executed.
-.TP 3
--
+.bP
If a translation
-into a request was done, \fBform_driver\fR returns the result of this request.
+into a request was done, \fBform_driver\fP returns the result of this request.
.RE
.PP
-If you clicked outside the user window or the mouse event couldn't be translated
-into a form request an \fBE_REQUEST_DENIED\fR is returned.
-.SS APPLICATION-DEFINED COMMANDS
+If you clicked outside the user window
+or the mouse event could not be translated
+into a form request an \fBE_REQUEST_DENIED\fP is returned.
+.SS Application-defined commands
.PP
-If the second argument is neither printable ASCII nor one of the above
+If the second argument is neither printable nor one of the above
pre-defined form requests, the driver assumes it is an application-specific
-command and returns \fBE_UNKNOWN_COMMAND\fR. Application-defined commands
-should be defined relative to \fBMAX_COMMAND\fR, the maximum value of these
+command and returns \fBE_UNKNOWN_COMMAND\fP. Application-defined commands
+should be defined relative to \fBMAX_COMMAND\fP, the maximum value of these
pre-defined requests.
.SH RETURN VALUE
-\fBform_driver\fR returns one of the following error codes:
+\fBform_driver\fP returns one of the following error codes:
.TP 5
.B E_OK
The routine succeeded.
.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\fP(3)).
.TP 5
.B E_UNKNOWN_COMMAND
The form driver code saw an unknown request code.
.
.SH SEE ALSO
-\fBcurses\fR(3X), \fBform\fR(3X).
+\fBcurses\fP(3X),
+\fBform\fP(3X),
+\fBform_fieldtype\fP(3X),
+\fBform_field_buffer\fP(3X),
+\fBform_field_validation\fP(3X),
+\fBform_variables\fP(3X),
+\fBgetch\fP(3X).
.SH NOTES
-The header file \fB<form.h>\fR automatically includes the header files
-\fB<curses.h>\fR.
+The header file \fB<form.h>\fP automatically includes the header files
+\fB<curses.h>\fP.
.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.