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.
+ 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-
@@ -87,7 +92,7 @@
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-
+ where it is not really needed. If insert/delete line can-
not be used, curses redraws the changed portions of all
lines.
@@ -99,66 +104,81 @@
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-
+ 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
- default.
+ 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.
-
- 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
+ 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. 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 to get the physical
- scrolling effect on the terminal, it is also necessary to
+ 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')
+ 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
+ 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.
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.
These functions are described in the XSI Curses standard,
Issue 4.
@@ -168,7 +188,7 @@
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.
+ 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
@@ -188,7 +208,7 @@