X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fresizeterm.3x;h=b88f68f351ff23a059271aaba3e97248e894cadd;hp=ceb49e3d1aa1770d323be6bb98821dc3ad2250b9;hb=59c1a9740d123db3cecafe76e18f7848081a670b;hpb=3a9b6a3bf0269231bef7de74757a910dedd04e0c diff --git a/man/resizeterm.3x b/man/resizeterm.3x index ceb49e3d..b88f68f3 100644 --- a/man/resizeterm.3x +++ b/man/resizeterm.3x @@ -1,69 +1,129 @@ -.\"***************************************************************************** -.\" Copyright 1996 by Thomas E. Dickey * -.\" All Rights Reserved. * -.\" * -.\" Permission to use, copy, modify, and distribute this software and its * -.\" documentation for any purpose and without fee is hereby granted, provided * -.\" that the above copyright notice appear in all copies and that both that * -.\" copyright notice and this permission notice appear in supporting * -.\" documentation, and that the name of the above listed copyright holder(s) * -.\" not be used in advertising or publicity pertaining to distribution of the * -.\" software without specific, written prior permission. THE ABOVE LISTED * -.\" COPYRIGHT HOLDER(S) DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * -.\" INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * -.\" EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY * -.\" SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER * -.\" RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF * -.\" CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN * -.\" CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * -.\"***************************************************************************** -.\" $Id: resizeterm.3x,v 1.3 1996/12/28 20:00:50 tom Exp $ +.\"*************************************************************************** +.\" Copyright (c) 1998-2013,2015 Free Software Foundation, Inc. * +.\" * +.\" Permission is hereby granted, free of charge, to any person obtaining a * +.\" copy of this software and associated documentation files (the * +.\" "Software"), to deal in the Software without restriction, including * +.\" without limitation the rights to use, copy, modify, merge, publish, * +.\" distribute, distribute with modifications, sublicense, and/or sell * +.\" copies of the Software, and to permit persons to whom the Software is * +.\" furnished to do so, subject to the following conditions: * +.\" * +.\" The above copyright notice and this permission notice shall be included * +.\" in all copies or substantial portions of the Software. * +.\" * +.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * +.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * +.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * +.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * +.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * +.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * +.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. * +.\" * +.\" Except as contained in this notice, the name(s) of the above copyright * +.\" holders shall not be used in advertising or otherwise to promote the * +.\" sale, use or other dealings in this Software without prior written * +.\" authorization. * +.\"*************************************************************************** +.\" +.\" Author: Thomas E. Dickey 1996-on +.\" +.\" $Id: resizeterm.3x,v 1.21 2015/09/26 19:55:32 tom Exp $ .TH resizeterm 3X "" -. +.de bP +.IP \(bu 4 +.. .SH NAME -\fBresizeterm\fR - change the curses terminal size -. +\fBis_term_resized\fR, +\fBresize_term\fR, +\fBresizeterm\fR \- change the curses terminal size .SH SYNOPSIS \fB#include \fR - +.sp +\fBbool is_term_resized(int lines, int columns);\fR +.br +\fBint resize_term(int lines, int columns);\fR +.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. - -When resizing the windows, the function blank-fills the areas that are -extended. The calling application should fill in these areas with -appropriate data. - -The function attempts to resize all windows. +the \fBncurses\fR library that record the window dimensions +such as the \fBLINES\fP and \fBCOLS\fP variables. +.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, +\fBresize_term\fR blank-fills the areas that are extended. +The calling application should fill in these areas with appropriate data. +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. -. +.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. .SH RETURN VALUE -The function returns the integer \fBERR\fR upon failure and \fBOK\fR on success. -It will fail if either of the dimensions less than or equal to zero, -or if an error occurs while (re)allocating memory for the windows. -. +Except as noted, these functions return +the integer \fBERR\fR upon failure and \fBOK\fR on success. +They will fail if either of the dimensions are less than or equal to zero, +or if an error occurs while (re)allocating memory for the windows. .SH NOTES -While this function is intended to be used to support a signal handler -(i.e., for SIGWINCH), care should be taken to avoid invoking it in a +While these functions are intended to be used to support a signal handler +(i.e., for SIGWINCH), care should be taken to avoid invoking them in a 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, +.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 -\fBwresize\fR(3x). -. +\fBcurs_getch\fR(3X), +\fBcurs_variables\fR(3X), +\fBwresize\fR(3X). .SH AUTHOR Thomas Dickey (from an equivalent function written in 1988 for BSD curses). -.\"# -.\"# The following sets edit modes for GNU EMACS -.\"# Local Variables: -.\"# mode:nroff -.\"# fill-column:79 -.\"# End: