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.
+ within curses. All options are initially FALSE, unless
+ otherwise stated. It is not necessary to turn these op-
+ tions 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-
+ 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
+ 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
+ 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
+ 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
+ where it is not 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
+ 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-
+ 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.
+ If immedok is called with TRUEasargument, any change in
+ the window image, such as the ones caused by waddch,wclr-
+ tobot,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 de-
+ fault.
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. If possible, the cursor is made invisible when
- this option is enabled.
-
- The setscrreg and wsetscrreg routines allow the applica-
+ the window cursor being refreshed. The leaveok option al-
+ lows 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.
+
+ 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
+ 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 bot-
+ tom 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 re-
+ gion 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 in order to get the
- physical scrolling effect on the terminal, it is also nec-
- essary to call idlok).
+ 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
+ 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')
+ 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-
+ 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
+ cursor motion. Also, curses will then be able to detect
the return key.
-
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.
+
+ The functions setscrreg and wsetscrreg return OK upon suc-
+ cess and ERR upon failure. All other routines that return
+ an integer always return OK.
+
+ X/Open 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 lim-
+ its extend outside the window.
+
+ X/Open does not define any error conditions. This imple-
+ mentation returns an error if the window pointer is null.
-
PORTABILITY
- These functions are described in the XSI Curses standard,
+
+ 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 in order to
- perform better vertical-motion optimization at wrefresh
- time.
+ 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 will not alter.
+
+ 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.
+ 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.
+ not. Use curs_set to make the cursor invisible.
-
NOTES
- Note that clearok, leaveok, scrollok, idcok, nl, nonl and
- setscrreg may be macros.
+
+ Note that clearok, leaveok, scrollok, idcok, nl, nonl and
+ setscrreg may be macros.
- The immedok routine is useful for windows that are used as
+ The immedok routine is useful for windows that are used as
terminal emulators.