.\"***************************************************************************.\" Copyright (c) 1998,2000,2001 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.                                                           *.\"***************************************************************************.\".\" $Id: curs_refresh.3x,v 1.10 2001/11/03 18:57:12 tom Exp $.TH curs_refresh 3X "".SH NAME\fBdoupdate\fR,\fBredrawwin\fR,\fBrefresh\fR,\fBwnoutrefresh\fR,\fBwredrawln\fR,\fBwrefresh\fR - refresh \fBcurses\fR windows and lines.SH SYNOPSIS\fB#include <curses.h>\fR\fBint refresh(void);\fR.br\fBint wrefresh(WINDOW *win);\fR.br\fBint wnoutrefresh(WINDOW *win);\fR.br\fBint doupdate(void);\fR.br\fBint redrawwin(WINDOW *win);\fR.br\fBint wredrawln(WINDOW *win, int beg_line, int num_lines);\fR.br.SH DESCRIPTIONThe \fBrefresh\fR and \fBwrefresh\fR routines (or \fBwnoutrefresh\fR and\fBdoupdate\fR) must be called to get actual output to the terminal, as otherroutines merely manipulate data structures.The routine \fBwrefresh\fR copiesthe named window to the physical terminal screen, taking into account what isalready there to do optimizations.The \fBrefresh\fR routine is thesame, using \fBstdscr\fR as the default window.Unless \fBleaveok\fR has beenenabled, the physical cursor of the terminal is left at the location of thecursor for that window.The \fBwnoutrefresh\fR and \fBdoupdate\fR routines allow multiple updates withmore efficiency than \fBwrefresh\fR alone.In addition to all the windowstructures, \fBcurses\fR keeps two data structures representing the terminalscreen: a physical screen, describing what is actually on the screen, and avirtual screen, describing what the programmer wants to have on the screen.The routine \fBwrefresh\fR works by first calling \fBwnoutrefresh\fR, whichcopies the named window to the virtual screen, and then calling \fBdoupdate\fR,which compares the virtual screen to the physical screen and does the actualupdate.If the programmer wishes to output several windows at once, a seriesof calls to \fBwrefresh\fR results in alternating calls to \fBwnoutrefresh\fRand \fBdoupdate\fR, causing several bursts of output to the screen.By firstcalling \fBwnoutrefresh\fR for each window, it is then possible to call\fBdoupdate\fR once, resulting in only one burst of output, with fewer totalcharacters transmitted and less CPU time used.If the \fIwin\fR argument to\fBwrefresh\fR is the global variable \fBcurscr\fR, the screen is immediatelycleared and repainted from scratch.The phrase "copies the named window to the virtual screen" above is ambiguous.What actually happens is that all \fItouched\fR (changed) lines in the windoware copied to the virtual screen.This affects programs that use overlappingwindows; it means that if two windows overlap, you can refresh them in eitherorder and the overlap region will be modified only when it is explicitlychanged.(But see the section on \fBPORTABILITY\fR below for a warning aboutexploiting this behavior.)The \fBwredrawln\fR routine indicates to \fBcurses\fR that some screen linesare corrupted and should be thrown away before anything is written over them.It touches the indicated lines (marking them changed).The routine \fBredrawwin\fR() touches the entire window..SH RETURN VALUERoutines that return an integer return \fBERR\fR upon failure, and \fBOK\fR(SVr4 only specifies "an integer value other than \fBERR\fR") upon successfulcompletion..SH NOTESNote that \fBrefresh\fR and \fBredrawwin\fR may be macros..SH PORTABILITYThe XSI Curses standard, Issue 4 describes these functions.Whether \fBwnoutrefresh()\fR copies to the virtual screen the entire contentsof a window or just its changed portions has never been well-documented inhistoric curses versions (including SVr4).It might be unwise to rely oneither behavior in programs that might have to be linked with other cursesimplementations.Instead, you can do an explicit \fBtouchwin()\fR before the\fBwnoutrefresh()\fR call to guarantee an entire-contents copy anywhere..SH SEE ALSO\fBcurses\fR(3X), \fBcurs_outopts\fR(3X).\"#.\"# The following sets edit modes for GNU EMACS.\"# Local Variables:.\"# mode:nroff.\"# fill-column:79.\"# End: