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- * @Id: curs_refresh.3x,v 1.17 2016/10/15 16:45:45 tom Exp @
+ * @Id: curs_refresh.3x,v 1.19 2018/07/28 22:59:02 tom Exp @
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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 physical terminal screen, taking into account what is al-
- ready there to do optimizations. The <STRONG>refresh</STRONG> routine is the same, us-
- ing <STRONG>stdscr</STRONG> as the default window. Unless <STRONG>leaveok</STRONG> has been enabled, the
- physical cursor of the terminal is left at the location of the cursor
- for that window.
+ 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: a physical screen, describing what is actually on the screen,
- and a virtual screen, describing what the programmer wants to have on
- the screen.
-
- The routine <STRONG>wrefresh</STRONG> works by first calling <STRONG>wnoutrefresh</STRONG>, which copies
- the named window to the virtual screen, and then calling <STRONG>doupdate</STRONG>,
- which compares the virtual screen to the physical screen 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 pos-
- sible to call <STRONG>doupdate</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 global variable <STRONG>curscr</STRONG>, the screen is
- immediately cleared and repainted from scratch.
+ 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
projects / ncurses.git / blobdiff