.\"***************************************************************************
-.\" Copyright 2020-2022,2023 Thomas E. Dickey *
+.\" Copyright 2020-2023,2024 Thomas E. Dickey *
.\" Copyright 1998-2015,2016 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_window.3x,v 1.43 2023/11/25 14:17:29 tom Exp $
-.TH curs_window 3X 2023-11-25 "ncurses 6.4" "Library calls"
-.de bP
-.ie n .IP \(bu 4
-.el .IP \(bu 2
-..
+.\" $Id: curs_window.3x,v 1.50 2024/05/25 20:43:47 tom Exp $
+.TH curs_window 3X 2024-05-25 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
.SH NAME
\fB\%newwin\fP,
\fB\%delwin\fP,
In this implementation
.TP 5
\fBdelwin\fP
-returns an error if the window pointer is null, or
+returns
+.B ERR
+if the window pointer is null, or
if the window is the parent of another window.
.TP 5
\fBderwin\fP
-returns an error if the parent window pointer is null, or
+returns
+.B ERR
+if the parent window pointer is null, or
if any of its ordinates or dimensions is negative, or
if the resulting window does not fit inside the parent window.
.TP 5
\fBdupwin\fP
-returns an error if the window pointer is null.
+returns
+.B ERR
+if the window pointer is null.
.IP
This implementation also maintains a list of windows,
and checks that the pointer passed to \fBdelwin\fP is one that
it created, returning an error if it was not..
.TP 5
\fBmvderwin\fP
-returns an error
+returns
+.B ERR
if the window pointer is null, or
if some part of the window would be placed off-screen.
.TP 5
\fBmvwin\fP
-returns an error
+returns
+.B ERR
if the window pointer is null, or
if the window is really a pad, or
if some part of the window would be placed off-screen.
if either the number of lines or columns is negative.
.TP 5
\fBsyncok\fP
-returns an error
+returns
+.B ERR
if the window pointer is null.
.TP 5
\fBsubwin\fP
-returns an error if the parent window pointer is null, or
+returns
+.B ERR
+if the parent window pointer is null, or
if any of its ordinates or dimensions is negative, or
if the resulting window does not fit inside the parent window.
.PP
.PP
Note that \fBsyncok\fP may be a macro.
.SH PORTABILITY
-The XSI Curses standard, Issue 4 describes these functions.
+X/Open Curses, Issue 4 describes these functions.
.PP
-X/Open Curses states regarding \fBdelwin\fP:
-.bP
-It must delete subwindows before deleting their parent.
-.bP
-If \fBdelwin\fP is asked to delete a parent window,
-it can only succeed if the curses library keeps a list of the subwindows.
-SVr4 curses kept a count of the number of subwindows rather than a list.
-It simply returned \fBERR\fP when asked to delete a subwindow.
-Solaris X/Open curses does not even make that check,
-and will delete a parent window which still has subwindows.
-.bP
-Since release 4.0 (1996), ncurses maintains a list of windows for each screen,
-to ensure that a window has no subwindows before allowing deletion.
-.bP
-NetBSD copied this feature of ncurses in 2003.
-.br
-PDCurses follows the scheme used in Solaris X/Open curses.
-.SH BUGS
-The subwindow functions
-\fB\%subwin\fP,
-\fB\%derwin\fP,
-\fB\%mvderwin\fP,
-\fB\%wsyncup\fP,
-\fB\%wsyncdown\fP,
-\fB\%wcursyncup\fP,
-and
-\fB\%syncok\fP
-are flaky,
-incompletely implemented,
-and not well tested.
+Regarding
+.IR \%delwin ","
+X/Open Curses states that
+.RS
+.PP
+[t]he application must delete subwindows before deleting the main
+window.
+.RE
+.PP
+If
+.I \%delwin
+is asked to delete a parent window,
+it can succeed only if the
+.I curses
+library keeps a list of its subwindows.
+SVr4
+.I curses
+kept a count of the number of subwindows rather than a list.
+It simply returned
+.B ERR
+when asked to delete a subwindow.
+Solaris X/Open
+.I curses
+.RI ( \%xcurses )
+does not make even that check,
+and will delete a parent window that still has subwindows.
+.I \%PDCurses
+also behaves this way.
.PP
-System\ V's \fIcurses\fP documentation is unclear about what
-\fB\%wsyncup\fP and \fB\%wsyncdown\fP actually do.
+.I \%ncurses
+4.0 (1996) and later maintains a list of windows for each screen
+to ensure that a window has no subwindows before allowing its deletion.
+NetBSD
+.I curses
+has followed suit since 2003.
+.PP
+SVr4
+.I curses
+documentation is unclear about what
+.I \%wsyncup
+and
+.I \%wsyncdown
+actually do.
It seems to imply that they are supposed to touch only those lines that
are affected by changes to a window's ancestors.
-The language here,
-and behavior of \fI\%ncurses\fP,
+The description and behavior of these functions in
+.I \%ncurses
is patterned on the X/Open Curses standard;
this approach may result in slower updates.
.SH SEE ALSO
projects / ncurses.git / blobdiff