.\"***************************************************************************
-.\" Copyright (c) 1998 Free Software Foundation, Inc. *
+.\" Copyright 2018,2020 Thomas E. Dickey *
+.\" Copyright 1998-2015,2017 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_touch.3x,v 1.6 1998/03/11 21:12:53 juergen Exp $
+.\" $Id: curs_touch.3x,v 1.23 2020/10/24 09:51:21 tom Exp $
.TH curs_touch 3X ""
+.na
+.hy 0
.SH NAME
-\fBtouchwin\fR, \fBtouchline\fR, \fBuntouchwin\fR,
-\fBwtouchln\fR, \fBis_linetouched\fR, \fBis_wintouched\fR -
-\fBcurses\fR refresh control routines
+\fBtouchwin\fR,
+\fBtouchline\fR,
+\fBuntouchwin\fR,
+\fBwtouchln\fR,
+\fBis_linetouched\fR,
+\fBis_wintouched\fR \- \fBcurses\fR refresh control routines
+.ad
+.hy
.SH SYNOPSIS
\fB#include <curses.h>\fR
+.sp
+\fBint touchline(WINDOW *\fP\fIwin\fP\fB, int \fP\fIstart\fP\fB, int \fP\fIcount\fP\fB);\fR
+.sp
+\fBint touchwin(WINDOW *\fP\fIwin\fP\fB);\fR
.br
-\fBint touchwin(WINDOW *win);\fR
+\fBint wtouchln(WINDOW *\fP\fIwin\fP\fB, int \fP\fIy\fP\fB, int \fP\fIn\fP\fB, int \fP\fIchanged\fP\fB);\fR
+.sp
+\fBint untouchwin(WINDOW *\fP\fIwin\fP\fB);\fR
+.sp
+\fBbool is_linetouched(WINDOW *\fP\fIwin\fP\fB, int \fP\fIline\fP\fB);\fR
.br
-\fBint touchline(WINDOW *win, int start, int count);\fR
-.br
-\fBint untouchwin(WINDOW *win);\fR
-.br
-\fBint wtouchln(WINDOW *win, int y, int n, int changed);\fR
-.br
-\fBint is_linetouched(WINDOW *win, int line);\fR
-.br
-\fBint is_wintouched(WINDOW *win);\fR
+\fBbool is_wintouched(WINDOW *\fP\fIwin\fP\fB);\fR
.br
.SH DESCRIPTION
The \fBtouchwin\fR and \fBtouchline\fR routines throw away all
optimization information about which parts of the window have been
-touched, by pretending that the entire window has been drawn on. This
+touched, by pretending that the entire window has been drawn on.
+This
is sometimes necessary when using overlapping windows, since a change
to one window affects the other window, but the records of which lines
-have been changed in the other window do not reflect the change. The
+have been changed in the other window do not reflect the change.
+The
routine \fBtouchline\fR only pretends that \fIcount\fR lines have been
changed, beginning with line \fIstart\fR.
-
+.PP
The \fBuntouchwin\fR routine marks all lines in the window as unchanged since
the last call to \fBwrefresh\fR.
-
+.PP
The \fBwtouchln\fR routine makes \fIn\fR lines in the window, starting
at line \fIy\fR, look as if they have (\fIchanged\fR\fB=1\fR) or have
not (\fIchanged\fR\fB=0\fR) been changed since the last call to
\fBwrefresh\fR.
-
+.PP
The \fBis_linetouched\fR and \fBis_wintouched\fR routines return
\fBTRUE\fR if the specified line/window was modified since the last
call to \fBwrefresh\fR; otherwise they return \fBFALSE\fR. In
All routines return the integer \fBERR\fR upon failure and an integer value
other than \fBERR\fR upon successful completion, unless otherwise noted in the
preceding routine descriptions.
+.PP
+X/Open does not define any error conditions.
+In this implementation
+.RS 3
+.TP 5
+\fBis_linetouched\fP
+returns an error
+if the window pointer is null, or
+if the line number is outside the window.
+.IP
+The constant \fBERR\fP is distinct from \fBTRUE\fP and \fBFALSE\fP,
+which are the normal return values of this function.
+Because the function returns a \fBbool\fP,
+returning \fBERR\fP (which is neither \fBTRUE\fP nor \fBFALSE\fP)
+may not be supported by the compiler.
+.IP
+To provide error-checking and also match the X/Open function prototype,
+the \fBERR\fP is provided by a macro named \fBis_linetouched\fP.
+The actual function returns \fBFALSE\fP when it detects an error.
+.TP 5
+\fBwtouchln\fP
+returns an error
+if the window pointer is null, or
+if the line number is outside the window.
+.RE
.SH PORTABILITY
-The XSI Curses standard, Issue 4 describes these functions.
-
-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.
+.PP
+These functions were introduced by SVr4.
+The Solaris curses header file,
+for instance, defines both an actual function and macro for each.
+The macros give the same result as the actual functions.
+SVr4 curses does not check the window parameter \fIwin\fP to ensure
+that it is not \fBNULL\fP;
+otherwise this implementation behaves the same as SVr4.
+.PP
+The XSI Curses standard, Issue 4 describes these functions,
+but defines no error conditions.
.SH NOTES
-Note that all routines except \fBwtouchln\fR may be macros.
+All of these routines except \fBwtouchln\fR may be macros.
.SH SEE ALSO
-\fBcurses\fR(3X), \fBcurs_refresh\fR(3X).
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+\fBcurses\fR(3X),
+\fBcurs_refresh\fR(3X),
+\fBcurs_variables\fR(3X).
projects / ncurses.git / blobdiff