Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
curs_outopts(3X)					      curs_outopts(3X)

       clearok,	idlok, idcok, immedok, leaveok,	setscrreg, wsetscrreg,
       scrollok, nl, nonl - curses output options

       #include	<curses.h>

       int clearok(WINDOW *win,	bool bf);
       int idlok(WINDOW	*win, bool bf);
       void idcok(WINDOW *win, bool bf);
       void immedok(WINDOW *win, bool bf);
       int leaveok(WINDOW *win,	bool bf);
       int setscrreg(int top, int bot);
       int wsetscrreg(WINDOW *win, int top, int	bot);
       int scrollok(WINDOW *win, bool bf);
       int nl(void);
       int nonl(void);

       These routines set options that change the style	of output within curs-
       es.   All  options are initially	FALSE, unless otherwise	stated.	 It is
       not necessary to	turn these options off before calling endwin(3X).

       If clearok is called with TRUE as argument, the next call  to  wrefresh
       with this window	will clear the screen completely and redraw the	entire
       screen from scratch.  This is useful when the contents  of  the	screen
       are  uncertain, or in some cases	for a more pleasing visual effect.  If
       the win argument	to clearok is the global  variable  curscr,  the  next
       call  to	 wrefresh  with	any window causes the screen to	be cleared and
       repainted from scratch.

       If idlok	is called with TRUE as second argument,	curses considers using
       the  hardware  insert/delete  line  feature  of	terminals so equipped.
       Calling idlok with FALSE	as second argument disables use	of line	inser-
       tion  and deletion.  This option	should be enabled only if the applica-
       tion needs insert/delete	line, for example, for a screen	editor.	 It is
       disabled	by default because insert/delete line tends to be visually an-
       noying when used	in applications	where it is not	really needed.	If in-
       sert/delete line	cannot be used,	curses redraws the changed portions of
       all lines.

       If idcok	is called with FALSE as	second argument, curses	no longer con-
       siders  using the hardware insert/delete	character feature of terminals
       so equipped.  Use of character insert/delete  is	 enabled  by  default.
       Calling	idcok with TRUE	as second argument re-enables use of character
       insertion and deletion.

       If immedok is called with TRUE as argument, any change  in  the	window
       image, such as the ones caused by waddch, wclrtobot, wscrl, etc., auto-
       matically cause a call to wrefresh.  However, it	 may  degrade  perfor-
       mance  considerably, due	to repeated calls to wrefresh.	It is disabled
       by default.

       Normally, the hardware cursor is	left at	the  location  of  the	window
       cursor  being  refreshed.   The	leaveok	option allows the cursor to be
       left wherever the update	happens	to leave it.  It is useful for	appli-
       cations	where  the  cursor  is not used, since it reduces the need for
       cursor motions.

       The setscrreg and wsetscrreg routines allow the application  programmer
       to set a	software scrolling region in a window.	The top	and bot	param-
       eters are the line  numbers  of	the  top  and  bottom  margin  of  the
       scrolling region.  (Line	0 is the top line of the window.)  If this op-
       tion and	scrollok are enabled, an attempt to move off the bottom	margin
       line causes all lines in	the scrolling region to	scroll one line	in the
       direction of the	first line.  Only the text of the window is  scrolled.
       (Note  that this	has nothing to do with the use of a physical scrolling
       region capability in the	terminal, like that in the VT100.  If idlok is
       enabled and the terminal	has either a scrolling region or insert/delete
       line capability,	they will probably be used by the output routines.)

       The scrollok option controls what happens when the cursor of  a	window
       is  moved  off  the edge	of the window or scrolling region, either as a
       result of a newline action on the bottom	line, or typing	the last char-
       acter of	the last line.	If disabled, (bf is FALSE), the	cursor is left
       on the bottom line.  If enabled,	(bf is TRUE), the window  is  scrolled
       up one line (Note that to get the physical scrolling effect on the ter-
       minal, it is also necessary to call idlok).

   nl, nonl
       The nl and nonl routines	control	whether	the underlying display	device
       translates  the return key into newline on input, and whether it	trans-
       lates newline into return and line-feed on output (in either case,  the
       call  addch('\n')  does	the  equivalent	of return and line feed	on the
       virtual screen).	 Initially, these translations do occur.  If you  dis-
       able  them  using  nonl,	 curses	will be	able to	make better use	of the
       line-feed capability, resulting in faster cursor	motion.	 Also,	curses
       will then be able to detect the return key.

       The  functions  setscrreg and wsetscrreg	return OK upon success and ERR
       upon failure.  All other	routines that return an	integer	always	return

       X/Open Curses does not define any error conditions.

       In this implementation, those functions that have a window pointer will
       return an error if the window pointer is	null.

		   returns an error if the cursor position is about to wrap.

		   returns an error if the scrolling region limits extend out-
		   side	the window.

       X/Open  does  not define	any error conditions.  This implementation re-
       turns an	error if the window pointer is null.

       These functions are described in	the XSI	Curses standard, Issue 4.

       The XSI Curses standard is ambiguous on the  question  of  whether  raw
       should  disable	the  CRLF translations controlled by nl	and nonl.  BSD
       curses did turn off these translations; AT&T curses (at least  as  late
       as  SVr1) did not.  We choose to	do so, on the theory that a programmer
       requesting raw input wants a clean  (ideally  8-bit  clean)  connection
       that the	operating system will not alter.

       Some  historic  curses implementations had, as an undocumented feature,
       the ability to do the equivalent	of clearok(...,	1)  by	saying	touch-
       win(stdscr) or clear(stdscr).  This will	not work under ncurses.

       Earlier	System	V  curses implementations specified that with scrollok
       enabled,	any window modification	triggering  a  scroll  also  forced  a
       physical	refresh.  XSI Curses does not require this, and	ncurses	avoids
       doing it	to perform better  vertical-motion  optimization  at  wrefresh

       The XSI Curses standard does not	mention	that the cursor	should be made
       invisible as a side-effect of leaveok.  SVr4 curses documentation  does
       this,  but  the code does not.  Use curs_set to make the	cursor invisi-

       Note that clearok, leaveok, scrollok, idcok, nl,	nonl and setscrreg may
       be macros.

       The immedok routine is useful for windows that are used as terminal em-

       curses(3X), curs_addch(3X), curs_clear(3X), curs_initscr(3X),
       curs_scroll(3X),	curs_refresh(3X), curs_variables(3X).



Want to link to this manual page? Use this URL:

home | help