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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 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 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  lab-
       num, 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  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).


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  inte-
       ger value, e.g., 32-bits.


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 ini-
               tialized.

          slk_attrset
               returns an error if the terminal or the softkeys were not  ini-
               tialized.

          slk_attr_set
               returns  an error if the terminal or the softkeys were not ini-
               tialized, 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 ini-
               tialized, 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  ini-
               tialized, 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

       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

       Most applications would use slk_noutrefresh because a wrefresh is like-
       ly 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-manipulation  functions
           slk_attron,  slk_attroff, slk_attrset, but which use attr_t parame-
           ters (rather than chtype), along with a reserved opts parameter.

           Two of these new functions (unlike the SVr4 functions) have no pro-
           vision for color: slk_attr_on and slk_attr_off.

           The third function (slk_attr_set) has a color-pair parameter.

       o   It added const qualifiers to parameters (unnecessarily), 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.  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

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



                                                                  curs_slk(3x)