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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | HISTORY | EXTENSIONS | NOTES | PORTABILITY | SEE ALSO | COLOPHON |
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curs_slk(3X) curs_slk(3X)
slk_init, slk_set, slk_wset, slk_refresh, slk_noutrefresh,
slk_label, slk_clear, slk_restore, slk_touch, slk_attron,
slk_attrset, slk_attroff, slk_attr_on, slk_attr_set,
slk_attr_off, slk_attr, slk_color, extended_slk_color - curses
soft label routines
#include <curses.h>
int slk_init(int fmt);
int slk_set(int labnum, const char *label, int fmt);
int slk_wset(int labnum, const wchar_t *label, int fmt);
char *slk_label(int labnum);
int slk_refresh(void);
int slk_noutrefresh(void);
int slk_clear(void);
int slk_restore(void);
int slk_touch(void);
int slk_attron(const chtype attrs);
int slk_attroff(const chtype attrs);
int slk_attrset(const chtype attrs);
int slk_attr_on(attr_t attrs, void* opts);
int slk_attr_off(const attr_t attrs, void * opts);
int slk_attr_set(const attr_t attrs, short pair, void* opts);
/* extension */
attr_t slk_attr(void);
int slk_color(short pair);
/* extension */
int extended_slk_color(int pair);
The slk* functions manipulate the set of soft function-key labels
that exist on many terminals. For those terminals that do not
have soft labels, curses takes over the bottom line of stdscr,
reducing the size of stdscr and the variable LINES. curses stan‐
dardizes on eight labels of up to eight characters each. In ad‐
dition to this, the ncurses implementation supports a mode where
it simulates 12 labels of up to five characters each. This is
useful for PC-like enduser devices. ncurses simulates this mode
by taking over up to two lines at the bottom of the screen; it
does not try to use any hardware support for this mode.
Initialization
The slk_init routine must be called before initscr or newterm is
called. If initscr eventually uses a line from stdscr to emulate
the soft labels, then fmt determines how the labels are arranged
on the screen:
0 indicates a 3-2-3 arrangement of the labels.
1 indicates a 4-4 arrangement
2 indicates the PC-like 4-4-4 mode.
3 is again the PC-like 4-4-4 mode, but in addition an index
line is generated, helping the user to identify the key
numbers easily.
Labels
The slk_set routine (and the slk_wset routine for the wide-char‐
acter library) has three parameters:
labnum
is the label number, from 1 to 8 (12 if fmt in slk_init
is 2 or 3);
label
is be the string to put on the label, up to eight (five
if fmt in slk_init is 2 or 3) characters in length. A
null string or a null pointer sets up a blank label.
fmt is either 0, 1, or 2, indicating whether the label is to
be left-justified, centered, or right-justified, respec‐
tively, within the label.
The slk_label routine returns the current label for label number
labnum, with leading and trailing blanks stripped.
Screen updates
The slk_refresh and slk_noutrefresh routines correspond to the
wrefresh and wnoutrefresh routines.
The slk_clear routine clears the soft labels from the screen.
The slk_restore routine restores the soft labels to the screen
after a slk_clear has been performed.
The slk_touch routine forces all the soft labels to be output the
next time a slk_noutrefresh is performed.
Video attributes
The slk_attron, slk_attrset, slk_attroff and slk_attr routines
correspond to attron, attrset, attroff and attr_get, respective‐
ly. They have an effect only if soft labels are simulated on the
bottom line of the screen. The default highlight for soft keys
is A_STANDOUT (as in System V curses, which does not document
this fact).
Colors
The slk_color routine corresponds to color_set. It has an effect
only if soft labels are simulated on the bottom line of the
screen.
Because slk_color accepts only short (signed 16-bit integer) val‐
ues, this implementation provides extended_slk_color which ac‐
cepts an integer value, e.g., 32-bits.
These routines return ERR upon failure and OK (SVr4 specifies on‐
ly "an integer value other than ERR") upon successful completion.
X/Open defines no error conditions. In this implementation
slk_attr
returns the attribute used for the soft keys.
slk_attroff, slk_attron, slk_clear, slk_noutrefresh,
slk_refresh, slk_touch
return an error if the terminal or the softkeys were not
initialized.
slk_attrset
returns an error if the terminal or the softkeys were not
initialized.
slk_attr_set
returns an error if the terminal or the softkeys were not
initialized, or the color pair is outside the range
0..COLOR_PAIRS-1.
slk_color
returns an error if the terminal or the softkeys were not
initialized, or the color pair is outside the range
0..COLOR_PAIRS-1.
slk_init
returns an error if the format parameter is outside the
range 0..3.
slk_label
returns NULL on error.
slk_set
returns an error if the terminal or the softkeys were not
initialized, or the labnum parameter is outside the range
of label counts, or if the format parameter is outside
the range 0..2, or if memory for the labels cannot be al‐
located.
SVr3 introduced these functions:
slk_clear
slk_init
slk_label
slk_noutrefresh
slk_refresh
slk_restore
slk_set
slk_touch
SVr4 added these functions:
slk_attroff
slk_attron
slk_attrset
slk_start
X/Open Curses added these:
slk_attr_off
slk_attr_on
slk_attr_set
slk_color
slk_wset
X/Open Curses documents the opts argument as reserved for future
use, saying that it must be null. This implementation uses that
parameter in ABI 6 for the functions which have a color-pair pa‐
rameter to support extended color pairs.
For functions which modify the color, e.g., slk_attr_set, if
opts is set it is treated as a pointer to int, and used to set
the color pair instead of the short pair parameter.
Most applications would use slk_noutrefresh because a wrefresh is
likely to follow soon.
The XSI Curses standard, Issue 4, described the soft-key func‐
tions, with some differences from SVr4 curses:
• It added functions like the SVr4 attribute-manipulation func‐
tions slk_attron, slk_attroff, slk_attrset, but which use at‐
tr_t parameters (rather than chtype), along with a reserved
opts parameter.
Two of these new functions (unlike the SVr4 functions) have
no provision for color: slk_attr_on and slk_attr_off.
The third function (slk_attr_set) has a color-pair parameter.
• It added const qualifiers to parameters (unnecessarily), and
• It added slk_color.
Although slk_start is declared in the curses header file, it was
not documented by SVr4 other than its presence in a list of
libtermlib.so.1 symbols. Reading the source code (i.e., Illu‐
mos):
• slk_start has two parameters:
• ng (number of groups) and
• gp (group pointer).
• Soft-key groups are an array of ng integers.
• In SVr4, slk_init calls slk_start passing a null for gp. For
this case, slk_start uses the number of groups ng (3 for the
3-2-3 layout, 2 for the 4-4 layout) which slk_init provided.
If ng is neither 2 or 3, slk_start checks the terminfo fln
(label_format) capability, interpreting that as a comma-sepa‐
rated list of numbers, e.g., “3,2,3” for the 3-2-3 layout.
Finally, if there is no fln capability, slk_start returns
ERR.
• If slk_start is given a non-null gp, it copies the ng ele‐
ments of the group of soft-keys, up to 16.
If there are more than 16 elements, slk_start returns an er‐
ror.
• The format codes 2 and 3 for slk_init were added by ncurses
in 1996. PDCurses 2.4 added this feature in 2001.
The function slk_attr was added by ncurses in 1996.
X/Open Curses does not specify a limit for the number of colors
and color pairs which a terminal can support. However, in its
use of short for the parameters, it carries over SVr4's implemen‐
tation detail for the compiled terminfo database, which uses
signed 16-bit numbers. This implementation provides extended
versions of those functions which use int parameters, allowing
applications to use larger color- and pair-numbers.
curses(3X), curs_attr(3X), curs_initscr(3X), curs_refresh(3X),
curs_variables(3X).
This page is part of the ncurses (new curses) project. Informa‐
tion about the project can be found at
⟨https://www.gnu.org/software/ncurses/ncurses.html⟩. If you have
a bug report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git mirror of the CVS repository
⟨https://github.com/mirror/ncurses.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2023-03-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
curs_slk(3X)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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