.\"***************************************************************************
-.\" Copyright (c) 1998 Free Software Foundation, Inc. *
+.\" Copyright 2018,2020 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_outopts.3x,v 1.13 1998/12/26 20:02:04 tom Exp $
+.\" $Id: curs_outopts.3x,v 1.33 2020/10/03 22:04:09 tom Exp $
.TH curs_outopts 3X ""
+.na
+.hy 0
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
.SH NAME
-\fBclearok\fR, \fBidlok\fR, \fBidcok immedok\fR,
-\fBleaveok\fR, \fBsetscrreg\fR, \fBwsetscrreg\fR, \fBscrollok\fR,
-\fBnl\fR, \fBnonl\fR - \fBcurses\fR output options
+\fBclearok\fR,
+\fBidlok\fR,
+\fBidcok\fR,
+\fBimmedok\fR,
+\fBleaveok\fR,
+\fBsetscrreg\fR,
+\fBwsetscrreg\fR,
+\fBscrollok\fR \- \fBcurses\fR output options
+.ad
+.hy
.SH SYNOPSIS
\fB#include <curses.h>\fR
-
-\fBint clearok(WINDOW *win, bool bf);\fR
+.sp
+\fBint clearok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
.br
-\fBint idlok(WINDOW *win, bool bf);\fR
+\fBint idlok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
.br
-\fBvoid idcok(WINDOW *win, bool bf);\fR
+\fBvoid idcok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
.br
-\fBvoid immedok(WINDOW *win, bool bf);\fR
+\fBvoid immedok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
.br
-\fBint leaveok(WINDOW *win, bool bf);\fR
+\fBint leaveok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
.br
-\fBint setscrreg(int top, int bot);\fR
+\fBint scrollok(WINDOW *\fP\fIwin\fP\fB, bool \fP\fIbf\fP\fB);\fR
+.sp
+\fBint setscrreg(int \fP\fItop\fP\fB, int \fP\fIbot\fP\fB);\fR
.br
-\fBint wsetscrreg(WINDOW *win, int top, int bot);\fR
-.br
-\fBint scrollok(WINDOW *win, bool bf);\fR
-.br
-\fBint nl(void);\fR
-.br
-\fBint nonl(void);\fR
+\fBint wsetscrreg(WINDOW *\fP\fIwin\fP\fB, int \fP\fItop\fP\fB, int \fP\fIbot\fP\fB);\fR
.br
.SH DESCRIPTION
+.PP
These routines set options that change the style of output within
-\fBcurses\fR. All options are initially \fBFALSE\fR, unless otherwise stated.
-It is not necessary to turn these options off before calling \fBendwin\fR.
-
+\fBcurses\fR.
+All options are initially \fBFALSE\fR, unless otherwise stated.
+It is not necessary to turn these options off before calling \fBendwin\fR(3X).
+.SS clearok
+.PP
If \fBclearok\fR is called with \fBTRUE\fR as argument, the next
call to \fBwrefresh\fR with this window will clear the screen completely and
-redraw the entire screen from scratch. This is useful when the contents of the
-screen are uncertain, or in some cases for a more pleasing visual effect. If
+redraw the entire screen from scratch.
+This is useful when the contents of the
+screen are uncertain, or in some cases for a more pleasing visual effect.
+If
the \fIwin\fR argument to \fBclearok\fR is the global variable \fBcurscr\fR,
the next call to \fBwrefresh\fR with any window causes the screen to be cleared
and repainted from scratch.
-
+.SS idlok
+.PP
If \fBidlok\fR is called with \fBTRUE\fR as second argument, \fBcurses\fR
considers using the hardware insert/delete line feature of terminals so
-equipped. Calling \fBidlok\fR with \fBFALSE\fR as second argument disables use
-of line insertion and deletion. This option should be enabled only if the
-application needs insert/delete line, for example, for a screen editor. It is
+equipped.
+Calling \fBidlok\fR with \fBFALSE\fR as second argument disables use
+of line insertion and deletion.
+This option should be enabled only if the
+application needs insert/delete line, for example, for a screen editor.
+It is
disabled by default because insert/delete line tends to be visually annoying
-when used in applications where it isn't really needed. If insert/delete line
+when used in applications where it is not really needed.
+If insert/delete line
cannot be used, \fBcurses\fR redraws the changed portions of all lines.
-
+.SS idcok
+.PP
If \fBidcok\fR is called with \fBFALSE\fR as second argument, \fBcurses\fR
no longer considers using the hardware insert/delete character feature of
-terminals so equipped. Use of character insert/delete is enabled by default.
+terminals so equipped.
+Use of character insert/delete is enabled by default.
Calling \fBidcok\fR with \fBTRUE\fR as second argument re-enables use
of character insertion and deletion.
-
+.SS immedok
+.PP
If \fBimmedok\fR is called with \fBTRUE as argument\fR, any change
in the window image, such as the ones caused by \fBwaddch, wclrtobot, wscrl\fR,
-\fIetc\fR., automatically cause a call to \fBwrefresh\fR. However, it may
+etc., automatically cause a call to \fBwrefresh\fR.
+However, it may
degrade performance considerably, due to repeated calls to \fBwrefresh\fR.
It is disabled by default.
-
+.SS leaveok
+.PP
Normally, the hardware cursor is left at the location of the window cursor
-being refreshed. The \fBleaveok\fR option allows the cursor to be left
-wherever the update happens to leave it. It is useful for applications where
-the cursor is not used, since it reduces the need for cursor motions. If
-possible, the cursor is made invisible when this option is enabled.
-
+being refreshed.
+The \fBleaveok\fR option allows the cursor to be left
+wherever the update happens to leave it.
+It is useful for applications where
+the cursor is not used, since it reduces the need for cursor motions.
+.SS scrollok
+.PP
+The \fBscrollok\fR option controls what happens when the cursor of a window is
+moved off the edge of the window or scrolling region, either as a result of a
+newline action on the bottom line, or typing the last character of the last
+line.
+If disabled, (\fIbf\fR is \fBFALSE\fR), the cursor is left on the bottom
+line.
+If enabled, (\fIbf\fR is \fBTRUE\fR), the window is scrolled up one line
+(Note that to get the physical scrolling effect on the terminal, it is
+also necessary to call \fBidlok\fR).
+.SS setscrreg/wsetscrreg
+.PP
The \fBsetscrreg\fR and \fBwsetscrreg\fR routines allow the application
-programmer to set a software scrolling region in a window. \fItop\fR and
-\fIbot\fR are the line numbers of the top and bottom margin of the scrolling
-region. (Line 0 is the top line of the window.) If this option and
+programmer to set a software scrolling region in a window.
+The \fItop\fR and
+\fIbot\fR parameters
+are the line numbers of the top and bottom margin of the scrolling
+region.
+(Line 0 is the top line of the window.) If this option and
\fBscrollok\fR are enabled, an attempt to move off the bottom margin line
causes all lines in the scrolling region to scroll one line in the direction
-of the first line. Only the text of the window is scrolled. (Note that this
+of the first line.
+Only the text of the window is scrolled.
+(Note that this
has nothing to do with the use of a physical scrolling region capability in the
-terminal, like that in the VT100. If \fBidlok\fR is enabled and the terminal
+terminal, like that in the VT100.
+If \fBidlok\fR is enabled and the terminal
has either a scrolling region or insert/delete line capability, they will
probably be used by the output routines.)
-
-The \fBscrollok\fR option controls what happens when the cursor of a window is
-moved off the edge of the window or scrolling region, either as a result of a
-newline action on the bottom line, or typing the last character of the last
-line. If disabled, (\fIbf\fR is \fBFALSE\fR), the cursor is left on the bottom
-line. If enabled, (\fIbf\fR is \fBTRUE\fR), the window is scrolled up one line
-(Note that in order to get the physical scrolling effect on the terminal, it is
-also necessary to call \fBidlok\fR).
-
-The \fBnl\fR and \fBnonl\fR routines control whether the underlying display
-device translates the return key into newline on input, and whether it
-translates newline into return and line-feed on output (in either case, the
-call \fBaddch('\\n')\fR does the equivalent of return and line feed on the
-virtual screen). Initially, these translations do occur. If you disable them
-using \fBnonl\fR, \fBcurses\fR will be able to make better use of the line-feed
-capability, resulting in faster cursor motion. Also, \fBcurses\fR will then be
-able to detect the return key.
.SH RETURN VALUE
The functions \fBsetscrreg\fR and \fBwsetscrreg\fR return \fBOK\fR upon success
-and \fBERR\fR upon failure. All other routines that return an integer always
+and \fBERR\fR upon failure.
+All other routines that return an integer always
return \fBOK\fR.
+.PP
+X/Open Curses does not define any error conditions.
+.PP
+In this implementation,
+.bP
+those functions that have a window pointer
+will return an error if the window pointer is null
+.bP
+\fBwsetscrreg\fP
+returns an error if the scrolling region limits extend outside the window.
+.RE
+.PP
+X/Open does not define any error conditions.
+This implementation returns an error
+if the window pointer is null.
.SH PORTABILITY
These functions are described in the XSI Curses standard, Issue 4.
-
-The XSI Curses standard is ambiguous on the question of whether \fBraw\fR()
-should disable the CRLF translations controlled by \fBnl\fR() and \fBnonl\fR().
-BSD curses did turn off these translations; AT&T curses (at least as late as
-SVr1) did not. We choose to do so, on the theory that a programmer requesting
-raw input wants a clean (ideally 8-bit clean) connection that the operating
-system does not mess with.
-
+.PP
+From the outset, ncurses used \fBnl\fP/\fBnonl\fP to control the conversion
+of newlines to carriage return/line-feed on output as well as input.
+XSI Curses documents only the use of these functions for input.
+This difference arose from converting the \fIpcurses\fP source
+(which used \fBioctl\fP calls with the \fBsgttyb\fP structure)
+to termios (i.e., the POSIX terminal interface).
+In the former, both input and output were controlled via a single
+option \fBCRMOD\fP,
+while the latter separates these features.
+Because that conversion interferes with output optimization,
+\fBnl\fP/\fBnonl\fP were amended after ncurses 6.2
+to eliminate their effect on output.
+.PP
Some historic curses implementations had, as an undocumented feature, the
ability to do the equivalent of \fBclearok(..., 1)\fR by saying
-\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR. This will not work under
-ncurses.
-
-Earlier System V curses implementations specified that with \fBscrollok\fR
+\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR.
+This will not work under ncurses.
+.PP
+Earlier System V curses implementations specified that with \fBscrollok\fR
enabled, any window modification triggering a scroll also forced a physical
-refresh. XSI Curses does not require this, and \fBncurses\fR avoids doing
-it in order to perform better vertical-motion optimization at \fBwrefresh\fR
+refresh.
+XSI Curses does not require this, and \fBncurses\fR avoids doing
+it to perform better vertical-motion optimization at \fBwrefresh\fR
time.
-
+.PP
The XSI Curses standard does not mention that the cursor should be
made invisible as a side-effect of \fBleaveok\fR.
SVr4 curses documentation does this, but the code does not.
+Use \fBcurs_set\fR to make the cursor invisible.
.SH NOTES
-Note that \fBclearok\fR, \fBleaveok\fR, \fBscrollok\fR, \fBidcok\fR, \fBnl\fR,
-\fBnonl\fR and \fBsetscrreg\fR may be macros.
-
+Note that
+\fBclearok\fR,
+\fBleaveok\fR,
+\fBscrollok\fR,
+\fBidcok\fR, and
+\fBsetscrreg\fR may be macros.
+.PP
The \fBimmedok\fR routine is useful for windows that are used as terminal
emulators.
.SH SEE ALSO
-\fBcurses\fR(3X), \fBcurs_addch\fR(3X), \fBcurs_clear\fR(3X),
-\fBcurs_initscr\fR(3X), \fBcurs_scroll\fR(3X), \fBcurs_refresh\fR(3X)
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+.na
+\fBcurses\fR(3X),
+\fBcurs_addch\fR(3X),
+\fBcurs_clear\fR(3X),
+\fBcurs_initscr\fR(3X),
+\fBcurs_scroll\fR(3X),
+\fBcurs_refresh\fR(3X),
+\fBcurs_variables\fR(3X).
projects / ncurses.git / blobdiff