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

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

   clearok
       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.

   idcok
       If idcok is called with FALSE  as  second  argument,  curses  no  longer  considers  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.

   idlok
       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
       insertion and deletion.  This option should be enabled only if the application needs insert/delete  line,
       for  example,  for  a  screen  editor.   It is disabled by default because insert/delete line tends to be
       visually annoying when used in applications where it is not really needed.  If insert/delete line  cannot
       be used, curses redraws the changed portions of all lines.

   immedok
       If  immedok  is  called  with  TRUE  as second argument, any change in the window image, such as the ones
       caused by waddch,wclrtobot,wscrl, etc., automatically causes a  call  to  wrefresh.   However,  it  may
       degrade  performance  considerably,  due  to  repeated  calls to wrefresh.  Calling immedok with FALSE as
       second argument restores the default behavior, i.e., deferring screen updates until a refresh is needed.

   leaveok
       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
       applications where the cursor is not used, since it reduces the need for cursor motions.

   scrollok
       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
       character  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 terminal, it is also necessary to call idlok).

   setscrreg,wsetscrreg
       The setscrreg and wsetscrreg routines allow the application programmer to set a software scrolling region
       in a window.  The top and bot parameters 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 option 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.)

       4BSD (1980) introduced clearok, leaveok, and scrollok.

       SVr2 (1984) supplied idlok, setscrreg, and wsetscrreg.

       SVr3.1 (1987) implemented idcok and immedok.

       ncurses   formerly  treated  nl  and  nonl  as  both  input  and  output  options,  but  no  longer;  see
       inopts(3NCURSES).

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

clearok, leaveok, scrollok, idcok, and setscrreg may be implemented as macros.

       The immedok routine is useful for windows that are used as terminal emulators.

       X/Open Curses Issue 4 describes these functions.  It specifies no error conditions for them.

       Some historic curses implementations, as an undocumented feature, did the equivalent of “clearok(...,1)”
       when touchwin(stdstr) or clear(stdstr) were used.  This trick does not work with ncurses.

       Early  System V  curses  implementations  specified  that  with scrollok enabled, any window modification
       triggering a scroll also forced a physical refresh.  X/Open Curses does not  require  this,  and  ncurses
       avoids doing so to better optimize vertical motions upon a wrefresh.

       X/Open  Curses  does  not  mention  that the cursor should be made invisible as a side-effect of leaveok.
       SVr4 curses documentation notes this, but the code neglects  it.   Use  curs_set(3NCURSES)  to  make  the
       cursor invisible.

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

       In this implementation,

       •   those functions that have a window pointer will return ERR if the window pointer is null

       •   wsetscrreg returns ERR if the scrolling region limits extend outside the window boundaries.

ncurses(3NCURSES),    addch(3NCURSES),     clear(3NCURSES),     initscr(3NCURSES),     refresh(3NCURSES),
       scroll(3NCURSES), curses_variables(3NCURSES)

ncurses 6.5                                        2025-02-01                                  outopts(3NCURSES)

#include<curses.h>intclearok(WINDOW*win,boolbf);voididcok(WINDOW*win,boolbf);intidlok(WINDOW*win,boolbf);voidimmedok(WINDOW*win,boolbf);intleaveok(WINDOW*win,boolbf);intscrollok(WINDOW*win,boolbf);intsetscrreg(inttop,intbot);intwsetscrreg(WINDOW*win,inttop,intbot);