Tribblix: manual page: curs

CURS_OUTOPTS(3CURSES) Curses Library Functions CURS_OUTOPTS(3CURSES)

NAME

curs_outopts, clearok, idlok, idcok, immedok, leaveok, setscrreg,
wsetscrreg, scrollok, nl, nonl - curses terminal output option
control routines

SYNOPSIS

cc [ flag ... ] file ... -lcurses [ library ... ]
#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
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 VALUES

setscrreg() and wsetscrreg() return OK upon success and ERR upon
failure. All other routines that return an integer always return OK.

ATTRIBUTES

NOTES