.TH curs_outopts 3X "" .SH NAME \fBclearok\fR, \fBidlok\fR, \fBidcok immedok\fR, \fBleaveok\fR, \fBsetscrreg\fR, \fBwsetscrreg\fR, \fBscrollok\fR, \fBnl\fR, \fBnonl\fR - \fBcurses\fR output options .SH SYNOPSIS \fB#include \fR \fBint clearok(WINDOW *win, bool bf);\fR .br \fBint idlok(WINDOW *win, bool bf);\fR .br \fBvoid idcok(WINDOW *win, bool bf);\fR .br \fBvoid immedok(WINDOW *win, bool bf);\fR .br \fBint leaveok(WINDOW *win, bool bf);\fR .br \fBint setscrreg(int top, int bot);\fR .br \fBint wsetscrreg(WINDOW *win, int top, int bot);\fR .br \fBint scrollok(WINDOW *win, bool bf);\fR .br \fBint nl(void);\fR .br \fBint nonl(void);\fR .br .SH DESCRIPTION These routines set options that change the style of output within \fBcurses\fR. All options are initially \fBFALSE\fR, unless otherwise stated. It is not necessary to turn these options off before calling \fBendwin\fR. If \fBclearok\fR is called with \fBTRUE\fR as argument, the next call to \fBwrefresh\fR 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 \fIwin\fR argument to \fBclearok\fR is the global variable \fBcurscr\fR, the next call to \fBwrefresh\fR with any window causes the screen to be cleared and repainted from scratch. If \fBidlok\fR is called with \fBTRUE\fR as argument, \fBcurses\fR considers using the hardware insert/delete line feature of terminals so equipped. If disabled (\fIbf\fR is \fBFALSE\fR), \fBcurses\fR very seldom uses this feature. (The insert/delete character feature is always considered.) 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 isn't really needed. If insert/delete line cannot be used, \fBcurses\fR redraws the changed portions of all lines. If \fBidcok\fR is called with \fBTRUE\fR as argument, \fBcurses\fR considers using the hardware insert/delete character feature of terminals so equipped. This is enabled by default. If \fBimmedok\fR is called with \fBTRUE as argument\fR, any change in the window image, such as the ones caused by \fBwaddch, wclrtobot, wscrl\fR, \fIetc\fR., automatically cause a call to \fBwrefresh\fR. However, it may degrade the performance considerably, due to repeated calls to \fBwrefresh\fR. It is disabled by default. Normally, the hardware cursor is left at the location of the window cursor being refreshed. The \fBleaveok\fR 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. If possible, the cursor is made invisible when this option is enabled. The \fBsetscrreg\fR and \fBwsetscrreg\fR routines allow the application programmer to set a software scrolling region in a window. \fItop\fR and \fIbot\fR 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 \fBscrollok\fR 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 \fBidlok\fR 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 \fBscrollok\fR 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, (\fIbf\fR is \fBFALSE\fR), the cursor is left on the bottom line. If enabled, (\fIbf\fR is \fBTRUE\fR), the window is scrolled up one line (Note that in order to get the physical scrolling effect on the terminal, it is also necessary to call \fBidlok\fR). The \fBnl\fR and \fBnonl\fR 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 \fBaddch('\n')\fR does the equivalent of return and line feed on the virtual screen). Initially, these translations do occur. If you disable them using \fBnonl\fR, \fBcurses\fR will be able to make better use of the line-feed capability, resulting in faster cursor motion. Also, \fBcurses\fR will then be able to detect the return key. .SH RETURN VALUE The functions \fBsetscrreg\fR and \fBwsetscrreg\fR return \fBOK\fR upon success and \fBERR\fR upon failure. All other routines that return an integer always return \fBOK\fR. .SH PORTABILITY These functions are described in the XSI Curses standard, Issue 4. The XSI Curses standard is ambiguous on the question of whether \fBraw\fR() should disable the CRLF translations controlled by \fBnl\fR() and \fBnonl\fR(). 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 undocumented feature, the ability to do the equivalent of \fBclearok(..., 1)\fR by saying \fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR. This will not work under curses. Earlier System V curses implementations specified that with \fBscrollok\fR enabled, any window modification triggering a scroll also forced a physical refresh. XSI Curses does not require this, and \fBcurses\fR avoids doing it in order to perform better vertical-motion optimization at \fBwrefresh\fR time. .SH NOTES Note that \fBclearok\fR, \fBleaveok\fR, \fBscrollok\fR, \fBidcok\fR, \fBnl\fR, \fBnonl\fR and \fBsetscrreg\fR may be macros. The \fBimmedok\fR routine is useful for windows that are used as terminal emulators. .SH SEE ALSO \fBcurses\fR(3X), \fBcurs_addch\fR(3X), \fBcurs_clear\fR(3X), \fBcurs_initscr\fR(3X), \fBcurs_scroll\fR(3X), \fBcurs_refresh\fR(3X) .\"# .\"# The following sets edit modes for GNU EMACS .\"# Local Variables: .\"# mode:nroff .\"# fill-column:79 .\"# End: