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<TITLE>Writing Programs with NCURSES</TITLE>
<link rev="made" href="mailto:bugs-ncurses@gnu.org">
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<esr@snark.thyrsus.com>
wrote many of the new features in versions after 1.8.1
and wrote most of this introduction.
-<A HREF="mailto:juergen.pfeifer@gmx.net">Jürgen Pfeifer</A>
+Jürgen Pfeifer
wrote all of the menu and forms code as well as the
<A HREF="http://www.adahome.com">Ada95</A> binding.
Ongoing work is being done by
-<A HREF="mailto:dickey@herndon4.his.com">Thomas Dickey</A>
-and
-<A HREF="mailto:juergen.pfeifer@gmx.net">Jürgen Pfeifer</A>.
-<A HREF="mailto:florian@gnu.org">Florian La Roche</A>
-acts as the maintainer for the Free Software Foundation, which holds the
-copyright on ncurses.
+<A HREF="mailto:dickey@invisible-island.net">Thomas Dickey</A> (maintainer).
Contact the current maintainers at
<A HREF="mailto:bug-ncurses@gnu.org">bug-ncurses@gnu.org</A>.
<P>
<li>xterm and similar programs such as rxvt.
<li>Linux console, when configured with <CODE>gpm</CODE>(1), Alessandro
Rubini's mouse server.
+<li>FreeBSD sysmouse (console)
<li>OS/2 EMX
</ul>
<P>
occurs a message is written to standard error and the program
exits. Otherwise it returns a pointer to stdscr. A few functions may be
called before initscr (<CODE>slk_init()</CODE>, <CODE>filter()</CODE>,
-<CODE>ripofflines()</CODE>, <CODE>use_env()</CODE>, and, if you are using multiple
+<CODE>ripoffline()</CODE>, <CODE>use_env()</CODE>, and, if you are using multiple
terminals, <CODE>newterm()</CODE>.)
<DT> <CODE>endwin()</CODE>
<DD> Your program should always call <CODE>endwin()</CODE> before exiting or
<CODE>newterm()</CODE> instead of <CODE>initscr()</CODE>. <CODE>newterm()</CODE> should
be called once for each terminal. It returns a variable of type
<CODE>SCREEN *</CODE> which should be saved as a reference to that
-terminal. The arguments are the type of the terminal (a string) and
+terminal.
+(NOTE: a SCREEN variable is not a <em>screen</em> in the sense we
+are describing in this introduction, but a collection of
+parameters used to assist in optimizing the display.)
+The arguments are the type of the terminal (a string) and
<CODE>FILE</CODE> pointers for the output and input of the terminal. If
type is NULL then the environment variable <CODE>$TERM</CODE> is used.
<CODE>endwin()</CODE> should called once at wrapup time for each terminal
structures. <CODE>wrefresh()</CODE> copies the named window to the physical
terminal screen, taking into account what is already
there in order to do optimizations. <CODE>refresh()</CODE> does a
-refresh of <CODE>stdscr()</CODE>. Unless <CODE>leaveok()</CODE> has been
+refresh of <CODE>stdscr</CODE>. Unless <CODE>leaveok()</CODE> has been
enabled, the physical cursor of the terminal is left at the
location of the window's cursor.
<DT> <CODE>doupdate()</CODE> and <CODE>wnoutrefresh(win)</CODE>
<H3><A NAME="xterm">Using NCURSES under XTERM</A></H3>
-A resize operation in X sends SIGWINCH to the application running under xterm.
-The <CODE>ncurses</CODE> 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. <P>
+A resize operation in X sends <CODE>SIGWINCH</CODE> to the application running
+under xterm.
-The easiest way to code your SIGWINCH handler is to have it do an
-<CODE>endwin</CODE>, followed by an <CODE>refresh</CODE> and a screen repaint you code
-yourself. The <CODE>refresh</CODE> will pick up the new screen size from the
+The easiest way to handle <CODE>SIGWINCH</CODE>
+is to do an <CODE>endwin</CODE>,
+followed by an <CODE>refresh</CODE> and a screen repaint you code
+yourself.
+The <CODE>refresh</CODE> will pick up the new screen size from the
xterm's environment. <P>
That is the standard way, of course (it even works with some vendor's curses
are limited to the new screen dimensions, and pads <CODE>stdscr</CODE>
with blanks if the screen is larger. <P>
-Finally, ncurses can be configured to provide its own SIGWINCH handler,
-based on <CODE>resizeterm</CODE>.
+The <CODE>ncurses</CODE> library provides a SIGWINCH signal handler,
+which pushes a <CODE>KEY_RESIZE</CODE> via the wgetch() calls.
+When <CODE>ncurses</CODE> returns that code,
+it calls <code>resizeterm</CODE>
+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
+<CODE>KEY_RESIZE</CODE> yourself.
<H3><A NAME="screens">Handling Multiple Terminal Screens</A></H3>
To understand why this is a problem, remember that screen updates are
calculated between two representations of the <EM>entire</EM> display. The
-documentation says that when you refresh a window, it is first copied to to the
+documentation says that when you refresh a window, it is first copied 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
The really clean way to handle this is to use the panels library. If,
when you want a screen update, you do <CODE>update_panels()</CODE>, it will
-do all the necessary <CODE>wnoutrfresh()</CODE> calls for whatever panel
+do all the necessary <CODE>wnoutrefresh()</CODE> calls for whatever panel
stacking order you have defined. Then you can do one <CODE>doupdate()</CODE>
and there will be a <EM>single</EM> burst of physical I/O that will do
all your updates.
<LI>Initialize <CODE>curses</CODE>.
<LI>Create the menu items, using <CODE>new_item()</CODE>.
<LI>Create the menu using <CODE>new_menu()</CODE>.
-<LI>Post the menu using <CODE>menu_post()</CODE>.
+<LI>Post the menu using <CODE>post_menu()</CODE>.
<LI>Refresh the screen.
<LI>Process user requests via an input loop.
-<LI>Unpost the menu using <CODE>menu_unpost()</CODE>.
+<LI>Unpost the menu using <CODE>unpost_menu()</CODE>.
<LI>Free the menu, using <CODE>free_menu()</CODE>.
<LI>Free the items using <CODE>free_item()</CODE>.
<LI>Terminate <CODE>curses</CODE>.
By default, both windows are <CODE>stdscr</CODE>. You can set them with the
functions in <CODE>menu_win(3x)</CODE>. <P>
-When you call <CODE>menu_post()</CODE>, you write the menu to its
-subwindow. When you call <CODE>menu_unpost()</CODE>, you erase the
+When you call <CODE>post_menu()</CODE>, you write the menu to its
+subwindow. When you call <CODE>unpost_menu()</CODE>, you erase the
subwindow, However, neither of these actually modifies the screen. To
do that, call <CODE>wrefresh()</CODE> or some equivalent.
<LI>Initialize <CODE>curses</CODE>.
<LI>Create the form fields, using <CODE>new_field()</CODE>.
<LI>Create the form using <CODE>new_form()</CODE>.
-<LI>Post the form using <CODE>form_post()</CODE>.
+<LI>Post the form using <CODE>post_form()</CODE>.
<LI>Refresh the screen.
<LI>Process user requests via an input loop.
-<LI>Unpost the form using <CODE>form_unpost()</CODE>.
+<LI>Unpost the form using <CODE>unpost_form()</CODE>.
<LI>Free the form, using <CODE>free_form()</CODE>.
<LI>Free the fields using <CODE>free_field()</CODE>.
<LI>Terminate <CODE>curses</CODE>.
greater). Note that these coordinates are relative to the form
subwindow, which will coincide with <CODE>stdscr</CODE> by default but
need not be <CODE>stdscr</CODE> if you've done an explicit
-<CODE>set_form_win
dow()</CODE> call. <P>
+<CODE>set_form_win()</CODE> call. <P>
The fifth argument allows you to specify a number of off-screen rows. If
this is zero, the entire field will always be displayed. If it is
from the last page goes to the first, and <CODE>REQ_PREV_PAGE</CODE> from
the first page goes to the last.
-<H3><A NAME="#ffield">Inter-Field Navigation Requests</A></H3>
+<H3><A NAME="ffield">Inter-Field Navigation Requests</A></H3>
These requests handle navigation between fields on the same page.
go to B only if A, B, and C <EM>all</EM> share the same first line;
otherwise it will skip over B to C.
-<H3><A NAME="#fifield">Intra-Field Navigation Requests</A></H3>
+<H3><A NAME="fifield">Intra-Field Navigation Requests</A></H3>
These requests drive movement of the edit cursor within the currently
selected field.
<DL>
<DT> O_NL_OVERLOAD
<DD> Enable overloading of <CODE>REQ_NEW_LINE</CODE> as described in <A
-NAME="fedit">Editing Requests</A>. The value of this option is
+href="#fedit">Editing Requests</A>. The value of this option is
ignored on dynamic fields that have not reached their size limit;
these have no last line, so the circumstances for triggering a
<CODE>REQ_NEXT_FIELD</CODE> never arise.
<DT> O_BS_OVERLOAD
<DD> Enable overloading of <CODE>REQ_DEL_PREV</CODE> as described in
-<A NAME="fedit">Editing Requests</A>.
+<A href="#fedit">Editing Requests</A>.
</DL>
The option values are bit-masks and can be composed with logical-or in
projects / ncurses.git / blobdiff