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* @Id: curs_outopts.3x,v 1.21 2007/06/02 20:40:07 tom Exp @
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<H1>curs_outopts 3x</H1>
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<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
<STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG> <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
</PRE>
<H2>NAME</H2><PRE>
<STRONG>clearok</STRONG>, <STRONG>idlok</STRONG>, <STRONG>idcok</STRONG>, <STRONG>immedok</STRONG>, <STRONG>leaveok</STRONG>, <STRONG>setscrreg</STRONG>,
<STRONG>wsetscrreg</STRONG>, <STRONG>scrollok</STRONG>, <STRONG>nl</STRONG>, <STRONG>nonl</STRONG> - <STRONG>curses</STRONG> output options
</PRE>
<H2>SYNOPSIS</H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>clearok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>int</STRONG> <STRONG>idlok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>void</STRONG> <STRONG>idcok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>void</STRONG> <STRONG>immedok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>int</STRONG> <STRONG>leaveok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>int</STRONG> <STRONG>setscrreg(int</STRONG> <STRONG>top,</STRONG> <STRONG>int</STRONG> <STRONG>bot);</STRONG>
<STRONG>int</STRONG> <STRONG>wsetscrreg(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>top,</STRONG> <STRONG>int</STRONG> <STRONG>bot);</STRONG>
<STRONG>int</STRONG> <STRONG>scrollok(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>bool</STRONG> <STRONG>bf);</STRONG>
<STRONG>int</STRONG> <STRONG>nl(void);</STRONG>
<STRONG>int</STRONG> <STRONG>nonl(void);</STRONG>
</PRE>
<H2>DESCRIPTION</H2><PRE>
These routines set options that change the style of output
within <STRONG>curses</STRONG>. All options are initially <STRONG>FALSE</STRONG>, unless
otherwise stated. It is not necessary to turn these op-
tions off before calling <STRONG>endwin</STRONG>.
If <STRONG>clearok</STRONG> is called with <STRONG>TRUE</STRONG> as argument, the next call
to <STRONG>wrefresh</STRONG> with this window will clear the screen com-
pletely 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
the <EM>win</EM> argument to <STRONG>clearok</STRONG> is the global variable <STRONG>curscr</STRONG>,
the next call to <STRONG>wrefresh</STRONG> with any window causes the
screen to be cleared and repainted from scratch.
If <STRONG>idlok</STRONG> is called with <STRONG>TRUE</STRONG> as second argument, <STRONG>curses</STRONG>
considers using the hardware insert/delete line feature of
terminals so equipped. Calling <STRONG>idlok</STRONG> with <STRONG>FALSE</STRONG> 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 edi-
tor. It is disabled by default because insert/delete line
tends to be visually annoying when used in applications
where it is not really needed. If insert/delete line can-
not be used, <STRONG>curses</STRONG> redraws the changed portions of all
lines.
If <STRONG>idcok</STRONG> is called with <STRONG>FALSE</STRONG> as second argument, <STRONG>curses</STRONG>
no longer considers using the hardware insert/delete char-
acter feature of terminals so equipped. Use of character
insert/delete is enabled by default. Calling <STRONG>idcok</STRONG> with
<STRONG>TRUE</STRONG> as second argument re-enables use of character inser-
tion and deletion.
If <STRONG>immedok</STRONG> is called with <STRONG>TRUE</STRONG> <STRONG>as</STRONG> <STRONG>argument</STRONG>, any change in
the window image, such as the ones caused by <STRONG>waddch,</STRONG> <STRONG>wclr-</STRONG>
<STRONG>tobot,</STRONG> <STRONG>wscrl</STRONG>, etc., automatically cause a call to <STRONG>wre-</STRONG>
<STRONG>fresh</STRONG>. However, it may degrade performance considerably,
due to repeated calls to <STRONG>wrefresh</STRONG>. It is disabled by de-
fault.
Normally, the hardware cursor is left at the location of
the window cursor being refreshed. The <STRONG>leaveok</STRONG> option al-
lows 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.
The <STRONG>setscrreg</STRONG> and <STRONG>wsetscrreg</STRONG> routines allow the applica-
tion programmer to set a software scrolling region in a
window. <EM>top</EM> and <EM>bot</EM> 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 <STRONG>scrollok</STRONG> are en-
abled, an attempt to move off the bottom margin line caus-
es 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 has nothing to do
with the use of a physical scrolling region capability in
the terminal, like that in the VT100. If <STRONG>idlok</STRONG> is enabled
and the terminal has either a scrolling region or in-
sert/delete line capability, they will probably be used by
the output routines.)
The <STRONG>scrollok</STRONG> 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, (<EM>bf</EM> is <STRONG>FALSE</STRONG>), the cursor is left
on the bottom line. If enabled, (<EM>bf</EM> is <STRONG>TRUE</STRONG>), the window
is scrolled up one line (Note that to get the physical
scrolling effect on the terminal, it is also necessary to
call <STRONG>idlok</STRONG>).
The <STRONG>nl</STRONG> and <STRONG>nonl</STRONG> 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 <STRONG>addch('\n')</STRONG>
does the equivalent of return and line feed on the virtual
screen). Initially, these translations do occur. If you
disable them using <STRONG>nonl</STRONG>, <STRONG>curses</STRONG> will be able to make bet-
ter use of the line-feed capability, resulting in faster
cursor motion. Also, <STRONG>curses</STRONG> will then be able to detect
the return key.
</PRE>
<H2>RETURN VALUE</H2><PRE>
The functions <STRONG>setscrreg</STRONG> and <STRONG>wsetscrreg</STRONG> return <STRONG>OK</STRONG> upon suc-
cess and <STRONG>ERR</STRONG> upon failure. All other routines that return
an integer always return <STRONG>OK</STRONG>.
X/Open does not define any error conditions.
In this implementation, those functions that have a window
pointer will return an error if the window pointer is
null.
<STRONG>wclrtoeol</STRONG>
returns an error if the cursor position is
about to wrap.
<STRONG>wsetscrreg</STRONG>
returns an error if the scrolling region lim-
its extend outside the window.
X/Open does not define any error conditions. This imple-
mentation returns an error if the window pointer is null.
</PRE>
<H2>PORTABILITY</H2><PRE>
These functions are described in the XSI Curses standard,
Issue 4.
The XSI Curses standard is ambiguous on the question of
whether <STRONG>raw</STRONG>() should disable the CRLF translations con-
trolled by <STRONG>nl</STRONG>() and <STRONG>nonl</STRONG>(). 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 will not alter.
Some historic curses implementations had, as an undocu-
mented feature, the ability to do the equivalent of
<STRONG>clearok(...,</STRONG> <STRONG>1)</STRONG> by saying <STRONG>touchwin(stdscr)</STRONG> or <STRONG>clear(std-</STRONG>
<STRONG>scr)</STRONG>. This will not work under ncurses.
Earlier System V curses implementations specified that
with <STRONG>scrollok</STRONG> enabled, any window modification triggering
a scroll also forced a physical refresh. XSI Curses does
not require this, and <STRONG>ncurses</STRONG> avoids doing it to perform
better vertical-motion optimization at <STRONG>wrefresh</STRONG> time.
The XSI Curses standard does not mention that the cursor
should be made invisible as a side-effect of <STRONG>leaveok</STRONG>.
SVr4 curses documentation does this, but the code does
not. Use <STRONG>curs_set</STRONG> to make the cursor invisible.
</PRE>
<H2>NOTES</H2><PRE>
Note that <STRONG>clearok</STRONG>, <STRONG>leaveok</STRONG>, <STRONG>scrollok</STRONG>, <STRONG>idcok</STRONG>, <STRONG>nl</STRONG>, <STRONG>nonl</STRONG> and
<STRONG>setscrreg</STRONG> may be macros.
The <STRONG>immedok</STRONG> routine is useful for windows that are used as
terminal emulators.
</PRE>
<H2>SEE ALSO</H2><PRE>
<STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>, <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>,
<STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>
<STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
</PRE>
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