- 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 wrefresh. However, it may degrade
- performance considerably, due to repeated calls to wrefresh. It is
- disabled by default.
+ If immedok is called with TRUE as second argument, any change in the
+ window image, such as the ones caused by waddch,wclrtobot,wscrl,
+ etc., automatically causes a call to wrefresh. However, it may degrade
+ performance considerably, due to repeated calls to wrefresh. Calling
+ immedok with FALSE as second argument restores the default behavior,
+ i.e., deferring screen updates until a refresh is needed.
- 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
+ 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 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
+ 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 setscrreg and wsetscrreg routines allow the application 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 bottom
+ The setscrreg and wsetscrreg routines allow the application 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 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
+ 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
+ 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 functions setscrreg and wsetscrreg return OK upon success and ERR
- upon failure. All other routines that return an integer always return
+ 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,
- o those functions that have a window pointer will return an error if
+ o those functions that have a window pointer will return an error if
the window pointer is null
- owsetscrreg returns an error if the scrolling region limits extend
+ owsetscrreg returns an error if the scrolling region limits extend
outside the window.
- X/Open does not define any error conditions. This implementation
+ X/Open does not define any error conditions. This implementation
returns an error if the window pointer is null.
These functions are described in the XSI Curses standard, Issue 4.
- From the outset, ncurses used nl/nonl to control the conversion of
- newlines to carriage return/line-feed on output as well as input. XSI
- Curses documents only the use of these functions for input. This
- difference arose from converting the pcurses source (which used ioctl
- calls with the sgttyb structure) to termios (i.e., the POSIX terminal
+ From the outset, ncurses used nl/nonl to control the conversion of
+ newlines to carriage return/line-feed on output as well as input. XSI
+ Curses documents only the use of these functions for input. This
+ difference arose from converting the pcurses source (which used ioctl
+ calls with the sgttyb structure) to termios (i.e., the POSIX terminal
interface). In the former, both input and output were controlled via a
single option CRMOD, while the latter separates these features.
- Because that conversion interferes with output optimization, nl/nonl
+ Because that conversion interferes with output optimization, nl/nonl
were amended after ncurses 6.2 to eliminate their effect on output.
- Some historic curses implementations had, as an undocumented feature,
+ Some historic curses implementations had, as an undocumented feature,
the ability to do the equivalent of clearok(...,1) by saying
touchwin(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
+ 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
+ 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 as a side-effect of leaveok. SVr4 curses documentation does
+ this, but the code does not. Use curs_set to make the cursor
invisible.
- Note that clearok, leaveok, scrollok, idcok, and setscrreg may be
+ Note that clearok, leaveok, scrollok, idcok, and setscrreg may be
macros.
- The immedok routine is useful for windows that are used as terminal
+ The immedok routine is useful for windows that are used as terminal
emulators.