* authorization. *
****************************************************************************
* Author: Thomas E. Dickey 1996-on
- * @Id: resizeterm.3x,v 1.31 2022/02/12 20:07:29 tom Exp @
+ * @Id: resizeterm.3x,v 1.32 2022/02/20 00:32:18 tom Exp @
-->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
This is an extension to the curses library. It provides callers with a
hook into the <STRONG>ncurses</STRONG> data to resize windows, primarily for use by
- programs running in an X Window terminal (e.g., xterm).
+ programs running in an X Window terminal (e.g., xterm) when the
+ terminal's screen size is changed by the user:
+ <STRONG>o</STRONG> Curses windows cannot extend outside the screen. If the terminal
+ is shrunk, curses windows must be shrunk to fit.
+
+ <STRONG>o</STRONG> If the terminal is stretched, rows and/or columns can be added to
+ existing windows. The added cells should match the current
+ attributes of the windows.
+
+ If the calling program has not set up a handler for <STRONG>SIGWINCH</STRONG> when it
+ initializes <STRONG>ncurses</STRONG> (e.g., using <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG> or <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG>), then
+ <STRONG>ncurses</STRONG> sets a handler for <STRONG>SIGWINCH</STRONG> which notifies the library when a
+ window-size event has occurred. The library checks for this
+ notification
+
+ <STRONG>o</STRONG> when reading input data,
+
+ <STRONG>o</STRONG> when implicitly resuming program mode (e.g., between <STRONG><A HREF="curs_initscr.3x.html">endwin(3x)</A></STRONG> and
+ <STRONG><A HREF="curs_refresh.3x.html">wrefresh(3x)</A></STRONG>), and
+
+ <STRONG>o</STRONG> when explicitly resuming program mode in <STRONG><A HREF="curs_terminfo.3x.html">restartterm(3x)</A></STRONG>.
+
+ When the library has found that the terminal's window-size has changed,
+ it calls <STRONG>resizeterm</STRONG> to update its data structures.
+
+ An application which establishes its own <STRONG>SIGWINCH</STRONG> handler can call
+ <STRONG>resizeterm</STRONG>, but in that case, the library will not see <STRONG>SIGWINCH</STRONG>, and
+ proper layout will rely upon the application.
+
+
+</PRE><H2><a name="h2-FUNCTIONS">FUNCTIONS</a></H2><PRE>
</PRE><H3><a name="h3-resizeterm">resizeterm</a></H3><PRE>
- The function <STRONG>resizeterm</STRONG> resizes the standard and current windows to the
- specified dimensions, and adjusts other bookkeeping data used by the
- <STRONG>ncurses</STRONG> library that record the window dimensions such as the <STRONG>LINES</STRONG> and
- <STRONG>COLS</STRONG> variables.
+ The function <STRONG>resizeterm</STRONG> resizes the standard and current windows (i.e.,
+ <STRONG>stdscr</STRONG> and <STRONG>curscr</STRONG>) to the specified dimensions, and adjusts other
+ bookkeeping data used by the <STRONG>ncurses</STRONG> library that record the window
+ dimensions such as the <STRONG>LINES</STRONG> and <STRONG>COLS</STRONG> variables.
</PRE><H3><a name="h3-resize_term">resize_term</a></H3><PRE>
- Most of the work is done by the inner function <STRONG>resize_term</STRONG>. The outer
- function <STRONG>resizeterm</STRONG> adds bookkeeping for the <STRONG>SIGWINCH</STRONG> handler, as well
- as repainting the soft-key area (see <STRONG><A HREF="curs_slk.3x.html">slk_touch(3x)</A></STRONG>).
+ Most of the work for <STRONG>resizeterm</STRONG> is done by the inner function
+ <STRONG>resize_term</STRONG>. The outer function <STRONG>resizeterm</STRONG> adds bookkeeping for the
+ <STRONG>SIGWINCH</STRONG> handler, as well as repainting the soft-key area (see
+ <STRONG><A HREF="curs_slk.3x.html">slk_touch(3x)</A></STRONG>).
+
+ The <STRONG>resize_term</STRONG> function attempts to resize all windows. This helps
+ with simple applications. However:
- When resizing the windows, <STRONG>resize_term</STRONG> blank-fills the areas that are
- extended. The calling application should fill in these areas with
- appropriate data.
+ <STRONG>o</STRONG> It is not possible to automatically resize pads.
- The <STRONG>resize_term</STRONG> function attempts to resize all windows. However, due
- to the calling convention of pads, it is not possible to resize these
- without additional interaction with the application.
+ <STRONG>o</STRONG> Applications which have complicated layouts should check for
+ <STRONG>KEY_RESIZE</STRONG> returned from <STRONG>wgetch</STRONG>, and adjust their layout, e.g.,
+ using <STRONG>wresize</STRONG> and <STRONG>mvwin</STRONG>, or by recreating the windows.
When resizing windows, <STRONG>resize_term</STRONG> recursively adjusts subwindows,
keeping them within the updated parent window's limits. If a top-level
<STRONG>o</STRONG> on receipt of a <STRONG>SIGWINCH</STRONG>, the handler sets a flag
- <STRONG>o</STRONG> which is tested in <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> and <STRONG>doupdate</STRONG>,
+ <STRONG>o</STRONG> which is tested in <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">doupdate(3x)</A></STRONG> and <STRONG><A HREF="curs_terminfo.3x.html">restartterm(3x)</A></STRONG>,
<STRONG>o</STRONG> in turn, calling the <STRONG>resizeterm</STRONG> function,
<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
-<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
+<li><a href="#h2-FUNCTIONS">FUNCTIONS</a>
<ul>
<li><a href="#h3-resizeterm">resizeterm</a></li>
<li><a href="#h3-resize_term">resize_term</a></li>
projects / ncurses.git / blobdiff