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| <H1 class="no-header">curs_refresh 3x</H1> |
| <PRE> |
| <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG> <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG> |
| |
| |
| |
| |
| </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE> |
| <STRONG>doupdate</STRONG>, <STRONG>redrawwin</STRONG>, <STRONG>refresh</STRONG>, <STRONG>wnoutrefresh</STRONG>, <STRONG>wredrawln</STRONG>, <STRONG>wrefresh</STRONG> - |
| refresh <STRONG>curses</STRONG> windows and lines |
| |
| |
| </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> |
| <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> |
| |
| <STRONG>int</STRONG> <STRONG>refresh(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wrefresh(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wnoutrefresh(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>doupdate(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>redrawwin(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wredrawln(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>beg_line,</STRONG> <STRONG>int</STRONG> <STRONG>num_lines);</STRONG> |
| |
| |
| </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE> |
| |
| </PRE><H3><a name="h3-refresh_wrefresh">refresh/wrefresh</a></H3><PRE> |
| The <STRONG>refresh</STRONG> and <STRONG>wrefresh</STRONG> routines (or <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG>) must |
| be called to get actual output to the terminal, as other routines mere- |
| ly manipulate data structures. The routine <STRONG>wrefresh</STRONG> copies the named |
| window to the <EM>physical</EM> <EM>screen</EM>, taking into account what is already |
| there to do optimizations. The <STRONG>refresh</STRONG> routine is the same, using <STRONG>std-</STRONG> |
| <STRONG>scr</STRONG> as the default window. Unless <STRONG>leaveok</STRONG> has been enabled, the physi- |
| cal cursor of the terminal is left at the location of the cursor for |
| that window. |
| |
| |
| </PRE><H3><a name="h3-wnoutrefresh_doupdate">wnoutrefresh/doupdate</a></H3><PRE> |
| The <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG> routines allow multiple updates with more |
| efficiency than <STRONG>wrefresh</STRONG> alone. In addition to all the window struc- |
| tures, <STRONG>curses</STRONG> keeps two data structures representing the terminal |
| screen: |
| |
| <STRONG>o</STRONG> a <EM>physical</EM> <EM>screen</EM>, describing what is actually on the screen, and |
| |
| <STRONG>o</STRONG> a <EM>virtual</EM> <EM>screen</EM>, describing what the programmer wants to have on |
| the screen. |
| |
| The routine <STRONG>wrefresh</STRONG> works by |
| |
| <STRONG>o</STRONG> first calling <STRONG>wnoutrefresh</STRONG>, which copies the named window to the |
| <EM>virtual</EM> <EM>screen</EM>, and |
| |
| <STRONG>o</STRONG> then calling <STRONG>doupdate</STRONG>, which compares the <EM>virtual</EM> <EM>screen</EM> to the |
| <EM>physical</EM> <EM>screen</EM> and does the actual update. |
| |
| If the programmer wishes to output several windows at once, a series of |
| calls to <STRONG>wrefresh</STRONG> results in alternating calls to <STRONG>wnoutrefresh</STRONG> and |
| <STRONG>doupdate</STRONG>, causing several bursts of output to the screen. By first |
| calling <STRONG>wnoutrefresh</STRONG> for each window, it is then possible to call <STRONG>doup-</STRONG> |
| <STRONG>date</STRONG> once, resulting in only one burst of output, with fewer total |
| characters transmitted and less CPU time used. |
| |
| If the <EM>win</EM> argument to <STRONG>wrefresh</STRONG> is the <EM>physical</EM> <EM>screen</EM> (i.e., the glob- |
| al variable <STRONG>curscr</STRONG>), the screen is immediately cleared and repainted |
| from scratch. |
| |
| The phrase "copies the named window to the virtual screen" above is am- |
| biguous. What actually happens is that all <EM>touched</EM> (changed) lines in |
| the window are copied to the virtual screen. This affects programs |
| that use overlapping windows; it means that if two windows overlap, you |
| can refresh them in either order and the overlap region will be modi- |
| fied only when it is explicitly changed. (But see the section on |
| <STRONG>PORTABILITY</STRONG> below for a warning about exploiting this behavior.) |
| |
| |
| </PRE><H3><a name="h3-wredrawln_redrawwin">wredrawln/redrawwin</a></H3><PRE> |
| The <STRONG>wredrawln</STRONG> routine indicates to <STRONG>curses</STRONG> that some screen lines are |
| corrupted and should be thrown away before anything is written over |
| them. It touches the indicated lines (marking them changed). The rou- |
| tine <STRONG>redrawwin</STRONG> touches the entire window. |
| |
| |
| </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE> |
| Routines that return an integer return <STRONG>ERR</STRONG> upon failure, and <STRONG>OK</STRONG> (SVr4 |
| only specifies "an integer value other than <STRONG>ERR</STRONG>") upon successful com- |
| pletion. |
| |
| X/Open does not define any error conditions. In this implementation |
| |
| <STRONG>wnoutrefresh</STRONG> |
| returns an error if the window pointer is null, or if the win- |
| dow is really a pad. |
| |
| <STRONG>wredrawln</STRONG> |
| returns an error if the associated call to <STRONG>touchln</STRONG> returns an |
| error. |
| |
| |
| </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> |
| Note that <STRONG>refresh</STRONG> and <STRONG>redrawwin</STRONG> may be macros. |
| |
| |
| </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE> |
| The XSI Curses standard, Issue 4 describes these functions. |
| |
| Whether <STRONG>wnoutrefresh</STRONG> copies to the virtual screen the entire contents |
| of a window or just its changed portions has never been well-documented |
| in historic curses versions (including SVr4). It might be unwise to |
| rely on either behavior in programs that might have to be linked with |
| other curses implementations. Instead, you can do an explicit <STRONG>touchwin</STRONG> |
| before the <STRONG>wnoutrefresh</STRONG> call to guarantee an entire-contents copy any- |
| where. |
| |
| |
| </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE> |
| <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG> <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>. |
| |
| |
| |
| <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG> |
| </PRE> |
| <div class="nav"> |
| <ul> |
| <li><a href="#h2-NAME">NAME</a></li> |
| <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li> |
| <li><a href="#h2-DESCRIPTION">DESCRIPTION</a> |
| <ul> |
| <li><a href="#h3-refresh_wrefresh">refresh/wrefresh</a></li> |
| <li><a href="#h3-wnoutrefresh_doupdate">wnoutrefresh/doupdate</a></li> |
| <li><a href="#h3-wredrawln_redrawwin">wredrawln/redrawwin</a></li> |
| </ul> |
| </li> |
| <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li> |
| <li><a href="#h2-NOTES">NOTES</a></li> |
| <li><a href="#h2-PORTABILITY">PORTABILITY</a></li> |
| <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> |
| </ul> |
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