The ncurses package was originated by Pavel Curtis. The original
maintainer of this package is Zeyd Ben-Halim <zmbenhal@netcom.com>.
Eric S. Raymond <esr@snark.thyrsus.com> wrote many of the new features
- in versions after 1.8.1 and wrote most of this introduction. Jürgen
+ in versions after 1.8.1 and wrote most of this introduction. Juergen
Pfeifer wrote all of the menu and forms code as well as the Ada95
binding. Ongoing work is being done by Thomas Dickey (maintainer).
Contact the current maintainers at bug-ncurses@gnu.org.
Here is a sample program to motivate the discussion:
#include <curses.h>
+#include <curses.h>
#include <signal.h>
static void finish(int sig);
Using NCURSES under XTERM
A resize operation in X sends SIGWINCH to the application running
- under xterm. The ncurses library provides an experimental signal
- handler, but in general does not catch this signal, because it cannot
- know how you want the screen re-painted. You will usually have to
- write the SIGWINCH handler yourself. Ncurses can give you some help.
-
- The easiest way to code your SIGWINCH handler is to have it do an
- endwin, followed by an refresh and a screen repaint you code yourself.
- The refresh will pick up the new screen size from the xterm's
- environment.
+ under xterm. The easiest way to handle SIGWINCH is to do an endwin,
+ followed by an refresh and a screen repaint you code yourself. The
+ refresh will pick up the new screen size from the xterm's environment.
That is the standard way, of course (it even works with some vendor's
curses implementations). Its drawback is that it clears the screen to
limited to the new screen dimensions, and pads stdscr with blanks if
the screen is larger.
- Finally, ncurses can be configured to provide its own SIGWINCH
- handler, based on resizeterm.
+ The ncurses library provides a SIGWINCH signal handler, which pushes a
+ KEY_RESIZE via the wgetch() calls. When ncurses returns that code, it
+ calls resizeterm to update the size of the standard screen's window,
+ repainting that (filling with blanks or truncating as needed). It also
+ resizes other windows, but its effect may be less satisfactory because
+ it cannot know how you want the screen re-painted. You will usually
+ have to write special-purpose code to handle KEY_RESIZE yourself.
Handling Multiple Terminal Screens
To understand why this is a problem, remember that screen updates are
calculated between two representations of the entire display. The
documentation says that when you refresh a window, it is first copied
- to to the virtual screen, and then changes are calculated to update
- the physical screen (and applied to the terminal). But "copied to" is
- not very specific, and subtle differences in how copying works can
- produce different behaviors in the case where two overlapping windows
- are each being refreshed at unpredictable intervals.
+ to the virtual screen, and then changes are calculated to update the
+ physical screen (and applied to the terminal). But "copied to" is not
+ very specific, and subtle differences in how copying works can produce
+ different behaviors in the case where two overlapping windows are each
+ being refreshed at unpredictable intervals.
What happens to the overlapping region depends on what wnoutrefresh()
does with its argument -- what portions of the argument window it
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