- 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.
-
- If clearok is called with TRUE as argument, the next call
- to wrefresh with this window will clear the screen com-
- pletely 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 insertion and deletion.
- This option should be enabled only if the application
- needs insert/delete line, for example, for a screen edi-
- tor. It is disabled by default because insert/delete line
- tends to be visually annoying when used in applications
- where it isn't really needed. If insert/delete line can-
- not be used, curses redraws the changed portions of all
- lines.
-
- If idcok is called with FALSE as second argument, curses
- no longer considers using the hardware insert/delete char-
- acter 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 inser-
- tion and deletion.
-
- If immedok is called with TRUEasargument, any change in
- the window image, such as the ones caused by waddch,
- wclrtobot,wscrl, etc., automatically cause a call to wre-
- fresh. However, it may degrade performance 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 applications where the cur-
- sor is not used, since it reduces the need for cursor
- motions.
-
- The setscrreg and wsetscrreg routines allow the applica-
- tion programmer to set a software scrolling region in a
- window. top and bot 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.)
-
- 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).
-
- The nl and nonl routines control whether the underlying
- display device translates the return key into newline on
- input, and whether it translates 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
- disable them using nonl, curses will be able to make bet-
- ter use of the line-feed capability, resulting in faster
- cursor motion. Also, curses will then be able to detect
- the return key.
+
+ 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 TRUEasargument, 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.
-
-
RETURN VALUE
- The functions setscrreg and wsetscrreg return OK upon suc-
- cess and ERR upon failure. All other routines that return
- an integer always return OK.
+
+ 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.)
-
-
PORTABILITY
- 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 con-
- trolled 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 does not mess with.
-
- Some historic curses implementations had, as an undocu-
- mented feature, the ability to do the equivalent of
- clearok(...,1) by saying touchwin(stdscr) or clear(std-
- scr). 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 time.
-
- 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 invisible.
+
+ 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).
-
-
NOTES
- 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 emulators.
+
+ 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
+ OK.
+
+ 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.
+
+ wclrtoeol
+ returns an error if the cursor position is about to wrap.
+ wsetscrreg
+ 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
+ time.
+ 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-
+ ble.
+
+ 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-
+ ulators.
+