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These routines set options that change the style of output within
curses. All options are initially #f, unless otherwise stated. It
is not necessary to turn these options off before calling endwin.
If clearok! is called with bf as #t, the next call
to refresh 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.
The return value is unspecified.
If idlok! is called with #t as second argument, curses
considers using the hardware insert/delete line feature of terminals
so equipped. Calling idlok! with bf as #f
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
isn’t really needed. If insert/delete line cannot be used, curses
redraws the changed portions of all lines.
The return value is unspecified.
If idcok! is called with bf as #f, 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 #t as second argument
re-enables use of character insertion and deletion.
The return value is unspecified.
If immedok! is called with #t as argument, any change in
the window image, such as the ones caused by addch,
clrtobot, scrl, etc., automatically cause a call to
refresh. However, it may degrade performance considerably,
due to repeated calls to refresh. It is disabled by default.
The return value is unspecified.
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.
The setscrreg! routine allows the application 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.)
Returns a two-element list that contains the line numbers of the top and bottom of the scroll region for the window win.
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 #f), the cursor
is left on the bottom line. If enabled, (bf is #t), 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 return value is unspecified.
The nl! and nonl! routines control whether the underlying
display device translates RET (return) into NL (newline)
on input, and whether it translates NL into RET and
LF (linefeed) output (in either case, the call (addch
(normal #\nl)) 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 better use
of the line-feed capability, resulting in faster cursor motion. Also,
curses will then be able to detect the return key.
The return values are unspecified.
There are a set of procedures to test the output options of a given window.
These test the output options of the window win and return
#t if they are set.
Next: Overlay and manipulate overlapped windows, Previous: Moving the cursor, Up: The basic curses library [Contents][Index]