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curs_slk 3x

curs_slk(3x)                                               curs_slk(3x)




NAME

       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

       #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

       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.


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 identi-
             fy 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-justi-
               fied, 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 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).


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  inte-
       ger)   values,   this   implementation   provides  extend-
       ed_slk_color  which  accepts  an  integer   value,   e.g.,
       32-bits.


RETURN VALUE

       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.


EXTENSIONS

       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.


NOTES

       Most applications would use slk_noutrefresh because a wre-
       fresh is likely to follow soon.


PORTABILITY

       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.


SEE ALSO

       curses(3x),  curs_attr(3x),   curs_initscr(3x),   curs_re-
       fresh(3x), curs_variables(3x).



                                                           curs_slk(3x)