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);
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 vari-
able LINES. curses standardizes on eight labels of up to
eight characters each. In addition to this, the ncurses
implementation supports a mode where it simulates 12 la-
bels 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.
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 identi-
fy the key numbers easily.
The slk_set routine (and the slk_wset routine for the
wide-character library) has three parameters:
labnum
is the label number, from 1 to 8 (12 for fmt in
slk_init is 2 or 3);
label
is be the string to put on the label, up to eight
(five for 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-justi-
fied, respectively, within the label.
The slk_label routine returns the current label for label
number labnum, with leading and trailing blanks stripped.
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.
The slk_attron, slk_attrset, slk_attroff and slk_attr rou-
tines correspond to attron, attrset, attroff and attr_get.
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).
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 inte-
ger) values, this implementation provides extend-
ed_slk_color which accepts an integer value, e.g.,
32-bits.
These routines return ERR upon failure and OK (SVr4 speci-
fies only "an integer value other than ERR") upon success-
ful completion.
X/Open defines no error conditions. In this implementa-
tion
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 out-
side 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 for-
mat parameter is outside the range 0..2, or if
memory for the labels cannot be allocated.
X/Open Curses documents the opts argument as reserved for
future use, saying that it must be null. This implementa-
tion uses that parameter in ABI 6 for the functions which
have a color-pair parameter to support extended color
pairs.
For functions which modify the color, e.g., slk_at-
tr_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 wre-
fresh is likely to follow soon.
The XSI Curses standard, Issue 4, described the soft-key
functions, with some differences from SVr4 curses:
o It added functions like the SVr4 attribute-manipula-
tion functions slk_attron, slk_attroff, slk_attrset,
but which use attr_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_at-
tr_off.
The third function (slk_attr_set) has a color-pair pa-
rameter.
o It added const qualifiers to parameters (unnecessari-
ly), and
o It added slk_color.
The format codes 2 and 3 for slk_init and the function
slk_attr are specific to ncurses.
X/Open Curses does not specify a limit for the number of
colors and color pairs which a terminal can support. How-
ever, in its use of short for the parameters, it carries
over SVr4's implementation detail for the compiled termin-
fo database, which uses signed 16-bit numbers. This im-
plementation provides extended versions of those functions
which use short parameters, allowing applications to use
larger color- and pair-numbers.
curses(3x), curs_attr(3x), curs_initscr(3x), curs_re-
fresh(3x), curs_variables(3x).
curs_slk(3x)