X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fresizeterm.3x;h=b88f68f351ff23a059271aaba3e97248e894cadd;hp=5730c05a9c290995c6dc5dfe2b485d87504d2919;hb=59c1a9740d123db3cecafe76e18f7848081a670b;hpb=0819b56c3096ed77dd36312b0c4e8f37e7d46c88

diff --git a/man/resizeterm.3x b/man/resizeterm.3x
index 5730c05a..b88f68f3 100644
--- a/man/resizeterm.3x
+++ b/man/resizeterm.3x
@@ -28,8 +28,11 @@
 .\"
 .\" Author: Thomas E. Dickey 1996-on
 .\"
-.\" $Id: resizeterm.3x,v 1.18 2015/04/11 10:23:49 tom Exp $
+.\" $Id: resizeterm.3x,v 1.21 2015/09/26 19:55:32 tom Exp $
 .TH resizeterm 3X ""
+.de bP
+.IP \(bu 4
+..
 .SH NAME
 \fBis_term_resized\fR,
 \fBresize_term\fR,
@@ -43,14 +46,18 @@
 .br
 \fBint resizeterm(int lines, int columns);\fR
 .SH DESCRIPTION
+.PP
 This is an extension to the curses library.
 It provides callers with a hook into the \fBncurses\fR data to resize windows,
 primarily for use by programs running in an X Window terminal (e.g., xterm).
+.SS resizeterm
+.PP
 The function \fBresizeterm\fR resizes the standard and current windows
 to the specified dimensions, and adjusts other bookkeeping data used by
 the \fBncurses\fR library that record the window dimensions
 such as the \fBLINES\fP and \fBCOLS\fP variables.
-.LP
+.SS resize_term
+.PP
 Most of the work is done by the inner function \fBresize_term\fR.
 The outer function \fBresizeterm\fR adds bookkeeping for the SIGWINCH handler.
 When resizing the windows,
@@ -60,7 +67,8 @@ The \fBresize_term\fR 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.
-.LP
+.SS is_term_resized
+.PP
 A support function \fBis_term_resized\fR is provided so that applications
 can check if the \fBresize_term\fR function would modify the window structures.
 It returns \fBTRUE\fP if the windows would be modified, and \fBFALSE\fP otherwise.
@@ -76,17 +84,43 @@ context where \fBmalloc\fR or \fBrealloc\fR may have been interrupted,
 since it uses those functions.
 .PP
 If ncurses is configured to supply its own SIGWINCH handler,
-the \fBresizeterm\fR function \fBungetch\fP's a \fBKEY_RESIZE\fR which
-will be read on the next call to \fBgetch\fR.
-This is used to alert an application that the screen size has changed,
+.bP
+on receipt of a SIGWINCH, the handler sets a flag
+.bP
+which is tested in \fBwgetch\fP and \fBdoupdate\fP,
+.bP
+in turn, calling the \fBresizeterm\fR function,
+.bP
+which \fBungetch\fP's a \fBKEY_RESIZE\fR which
+will be read on the next call to \fBwgetch\fR.
+.IP
+The \fBKEY_RESIZE\fP alerts an application that the screen size has changed,
 and that it should repaint special features such as pads that cannot
 be done automatically.
+.IP
+Calling \fBresizeterm\fP or \fBresize_term\fP
+directly from a signal handler is unsafe.
+This indirect method is used to provide a safe way to resize the ncurses
+data structures.
 .PP
 If the environment variables \fBLINES\fP or \fBCOLUMNS\fP are set,
 this overrides the library's use of the window size obtained from
 the operating system.
 Thus, even if a SIGWINCH is received,
 no screen size change may be recorded.
+.SH PORTABILITY
+.PP
+It is possible to resize the screen with SVr4 curses,
+by
+.bP
+exiting curses with \fBendwin\fP(3X) and
+.bP
+resuming using \fBrefresh\fP(3X).
+.PP
+Doing that clears the screen and is visually distracting.
+.PP
+This extension of ncurses was introduced in mid-1995.
+It was adopted in NetBSD curses (2001) and PDCurses (2003).
 .SH SEE ALSO
 \fBcurs_getch\fR(3X),
 \fBcurs_variables\fR(3X),