slk(3NCURSES)slk(3NCURSES)NAME
slk_init, slk_set, 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 - curses
soft label routines
SYNOPSIS
#include <curses.h>
int slk_init(int fmt);
int slk_set(int labnum, const char *label, int fmt);
int slk_refresh(void);
int slk_noutrefresh(void);
char *slk_label(int labnum);
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 color_pair_number, void* opts);
attr_t slk_attr(void);
int slk_color(short color_pair_number);
DESCRIPTION
The slk* functions manipulate the set of soft function-key labels that
exist on many terminals. For those terminals that do not have soft la‐
bels, curses takes over the bottom line of stdscr, reducing the size of
stdscr and the variable LINES. curses standardizes on eight labels of
up to eight characters each. In addition to this, the ncurses imple‐
mentation supports a mode where it simulates 12 labels of up to five
characters each. This is useful for today's PC-like enduser devices.
ncurses simulates this mode by taking over up to two lines at the bot‐
tom 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 identify the key num‐
bers easily.
The slk_set routine 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-justified, respectively,
within the label.
The slk_refresh and slk_noutrefresh routines correspond to the wrefresh
and wnoutrefresh routines.
The slk_label routine returns the current label for label number lab‐
num, with leading and trailing blanks stripped.
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 routines corre‐
spond 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 curs‐
es, 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.
RETURN VALUE
These routines return ERR upon failure and OK (SVr4 specifies only "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..COL‐
OR_PAIRS-1, or opts is not null.
slk_color
returns an error if the terminal or the softkeys were not
initialized, or the color pair is outside the range 0..COL‐
OR_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 allocat‐
ed.
NOTES
Most applications would use slk_noutrefresh because a wrefresh is like‐
ly to follow soon.
PORTABILITY
The XSI Curses standard, Issue 4, describes these functions. It
changes the argument type of the attribute-manipulation functions
slk_attron, slk_attroff, slk_attrset to be attr_t, and adds const qual‐
ifiers. The format codes 2 and 3 for slk_init() and the function
slk_attr are specific to ncurses.
SEE ALSOncurses(3NCURSES), attr(3NCURSES), initscr(3NCURSES), refresh(3NCURSES)slk(3NCURSES)
