diff options
Diffstat (limited to 'man/curs_touch.3x')
| -rw-r--r-- | man/curs_touch.3x | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/man/curs_touch.3x b/man/curs_touch.3x index 9fa6d370b9a2..1d2bb8ee7a58 100644 --- a/man/curs_touch.3x +++ b/man/curs_touch.3x @@ -1,5 +1,5 @@ .\"*************************************************************************** -.\" Copyright (c) 1998-2006,2010 Free Software Foundation, Inc. * +.\" Copyright (c) 1998-2017,2018 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 * @@ -26,7 +26,7 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: curs_touch.3x,v 1.14 2010/12/04 18:38:55 tom Exp $ +.\" $Id: curs_touch.3x,v 1.21 2018/07/28 21:34:56 tom Exp $ .TH curs_touch 3X "" .na .hy 0 @@ -57,10 +57,12 @@ .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 @@ -84,13 +86,22 @@ preceding routine descriptions. .PP X/Open does not define any error conditions. In this implementation -.RS +.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. -Note that ERR is distinct from TRUE and FALSE, which are the normal return values of this function. +.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 @@ -98,14 +109,19 @@ 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. .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. +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), |