curs_outopts(3X) curs_outopts(3X)
NAME
cursoutopts: clearok, idlok, idcok immedok, leaveok, setscrreg,
wsetscrreg, scrollok, nl, nonl - curses terminal output option
control routines
SYNOPSIS
#include <curses.h>
int clearok(WINDOW *win, bool bf);
int idlok(WINDOW *win, bool bf);
void idcok(WINDOW *win, bool bf);
void immedok(WINDOW *win, bool bf);
int leaveok(WINDOW *win, bool bf);
int setscrreg(int top, int bot);
int wsetscrreg(WINDOW *win, int top, int bot);
int scrollok(WINDOW *win, bool bf);
int nl(void);
int nonl(void);
DESCRIPTION
These routines set options that deal with output within curses. All
options are initially FALSE, unless otherwise stated. It is not
necessary to turn these options off before calling endwin.
With the clearok routine, if enabled (bf is TRUE), the next call to
wrefresh with this window will clear the screen completely 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 win argument to clearok is the global variable
curscr, the next call to wrefresh with any window causes the screen
to be cleared and repainted from scratch.
With the idlok routine, if enabled (bf is TRUE), curses considers
using the hardware insert/delete line feature of terminals so
equipped. If disabled (bf is FALSE), curses very seldom uses this
feature. (The insert/delete character feature is always considered.)
This option should be enabled only if the application needs
insert/delete line, for example, for a screen editor. It is disabled
by default because insert/delete line tends to be visually annoying
when used in applications where it isn't really needed. If
insert/delete line cannot be used, curses redraws the changed
portions of all lines.
With the idcok routine, if enabled (bf is TRUE), curses considers
using the hardware insert/delete character feature of terminals so
equipped. This is enabled by default.
With the immedok routine, if enabled (bf is TRUE), any change in the
window image, such as the ones caused by waddch, wclrtobot, wscrl,
etc., automatically cause a call to wrefresh. However, it may
degrade the performance considerably, due to repeated calls to
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curs_outopts(3X) curs_outopts(3X)
wrefresh. It is disabled by default.
Normally, the hardware cursor is left at the location of the window
cursor being refreshed. The leaveok option allows 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. If possible, the cursor is made invisible when
this option is enabled.
The setscrreg and wsetscrreg routines allow the application
programmer to set a software scrolling region in a window. top and
bot 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 scrollok are enabled, an attempt to move off the bottom
margin line causes all lines in the scrolling region to scroll up one
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 idlok is enabled and the
terminal has either a scrolling region or insert/delete line
capability, they will probably be used by the output routines.)
The scrollok 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, (bf is FALSE), the cursor
is left on the bottom line. If enabled, (bf is TRUE), wrefresh is
called on the window, and the physical terminal and window are
scrolled up one line. [Note that in order to get the physical
scrolling effect on the terminal, it is also necessary to call
idlok.]
The nl and nonl routines control whether newline is translated into
carriage return and linefeed on output, and whether return is
translated into newline on input. Initially, the translations do
occur. By disabling these translations using nonl, curses is able to
make better use of the linefeed capability, resulting in faster
cursor motion.
RETURN VALUE
setscrreg and wsetscrreg return OK upon success and ERR upon failure.
All other routines that return an integer always return OK.
NOTES
The header file <curses.h> automatically includes the header files
<stdio.h> and <unctrl.h>.
Note that clearok, leaveok, scrollok, idcok, nl, nonl and setscrreg
may be macros.
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curs_outopts(3X) curs_outopts(3X)
The immedok routine is useful for windows that are used as terminal
emulators.
SEE ALSO
curses(3X), cursaddch(3X), cursclear(3X), cursinitscr(3X),
cursscroll(3X), cursrefresh(3X).
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