NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXTENSIONS | NOTES | PORTABILITY | SEE ALSO | COLOPHON

curs_slk(3X)                                                    curs_slk(3X)

NAME         top

       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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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 standardizes on
       eight labels of up to eight characters each.  In addition 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-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-justified, respectively,
               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.  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) values,
       this implementation provides extended_slk_color which accepts an
       integer value, e.g., 32-bits.

RETURN VALUE         top

       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 ini‐
               tialized.

          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.

          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 allocated.

EXTENSIONS         top

       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 parameter 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.

NOTES         top

       Most applications would use slk_noutrefresh because a wrefresh is
       likely to follow soon.

PORTABILITY         top

       The XSI Curses standard, Issue 4, described the soft-key functions,
       with some differences from SVr4 curses:

       ·   It added functions like the SVr4 attribute-manipulation 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_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.

       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.  However, in its use of
       short for the parameters, it carries over SVr4's implementation
       detail for the compiled terminfo database, which uses signed 16-bit
       numbers.  This implementation provides extended versions of those
       functions which use short parameters, allowing applications to use
       larger color- and pair-numbers.

SEE ALSO         top

       curses(3X), curs_attr(3X), curs_initscr(3X), curs_refresh(3X),
       curs_variables(3X).

COLOPHON         top

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                                                                curs_slk(3X)