.\"***************************************************************************
-.\" Copyright (c) 1998 Free Software Foundation, Inc. *
+.\" Copyright (c) 1998-2010,2018 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_scroll.3x,v 1.6 1998/03/11 21:12:53 juergen Exp $
+.\" $Id: curs_scroll.3x,v 1.16 2018/07/28 22:59:02 tom Exp $
.TH curs_scroll 3X ""
+.na
+.hy 0
.SH NAME
-\fBscroll\fR, \fBsrcl\fR, \fBwscrl\fR - scroll a \fBcurses\fR window
+\fBscroll\fR,
+\fBscrl\fR,
+\fBwscrl\fR \- scroll a \fBcurses\fR window
+.ad
+.hy
.SH SYNOPSIS
\fB#include <curses.h>\fR
-
+.sp
\fBint scroll(WINDOW *win);\fR
.br
\fBint scrl(int n);\fR
\fBint wscrl(WINDOW *win, int n);\fR
.br
.SH DESCRIPTION
-The \fBscroll\fR routine scrolls the window up one line. This involves moving
-the lines in the window data structure. As an optimization, if the scrolling
-region of the window is the entire screen, the physical screen may be scrolled
-at the same time.
-
+The \fBscroll\fR routine scrolls the window up one line.
+This involves moving
+the lines in the window data structure.
+As an optimization, if the scrolling
+region of the window is the entire screen,
+the \fIphysical screen\fP may be scrolled at the same time.
+.PP
For positive \fIn\fR, the \fBscrl\fR and \fBwscrl\fR routines scroll the
window up \fIn\fR lines (line \fIi\fR+\fIn\fR becomes \fIi\fR); otherwise
-scroll the window down \fIn\fR lines. This involves moving the lines in the
-window character image structure. The current cursor position is not changed.
-
+scroll the window down \fIn\fR lines.
+This involves moving the lines in the
+window character image structure.
+The current cursor position is not changed.
+.PP
For these functions to work, scrolling must be enabled via \fBscrollok\fR.
.SH RETURN VALUE
These routines return \fBERR\fR upon failure, and \fBOK\fR (SVr4 only specifies
"an integer value other than \fBERR\fR") upon successful completion.
+.PP
+X/Open defines no error conditions.
+.PP
+This implementation returns an error
+if the window pointer is null, or
+if scrolling is not enabled in the window, e.g., with \fBscrollok\fP.
.SH NOTES
Note that \fBscrl\fR and \fBscroll\fR may be macros.
-
-The SVr4 documentation says that the optimization of physically scrolling
+.PP
+The SVr4 documentation says that the optimization of physically scrolling
immediately if the scroll region is the entire screen "is" performed, not
-"may be" performed. This implementation deliberately does not guarantee
-that this will occur, in order to leave open the possibility of smarter
-optimization of multiple scroll actions on the next update.
-
-Neither the SVr4 documentation specifies whether the current attribute or
+"may be" performed.
+This implementation deliberately does not guarantee
+that this will occur, to leave open the possibility of smarter
+optimization of multiple scroll actions on the next update.
+.PP
+Neither the SVr4 nor the XSI documentation specify whether the current
+attribute or
current color-pair of blanks generated by the scroll function is zeroed.
Under this implementation it is.
.SH PORTABILITY
The XSI Curses standard, Issue 4 describes these functions.
.SH SEE ALSO
\fBcurses\fR(3X), \fBcurs_outopts\fR(3X)
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
projects / ncurses.git / blobdiff