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+ * Copyright 2018-2020,2021 Thomas E. Dickey *
+ * Copyright 1998-2015,2017 Free Software Foundation, Inc. *
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- * @Id: curs_bkgd.3x,v 1.28 2018/12/09 00:45:05 tom Exp @
+ * @Id: curs_bkgd.3x,v 1.32 2021/06/17 21:30:22 tom Exp @
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-<H1 class="no-header">curs_bkgd 3x</H1>
+<H1 class="no-header">curs_bkgd 3X</H1>
<PRE>
-<STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG> <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>
+<B><A HREF="curs_bkgd.3X.html">curs_bkgd(3X)</A></B> <B><A HREF="curs_bkgd.3X.html">curs_bkgd(3X)</A></B>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
- <STRONG>bkgdset</STRONG>, <STRONG>wbkgdset</STRONG>, <STRONG>bkgd</STRONG>, <STRONG>wbkgd</STRONG>, <STRONG>getbkgd</STRONG> - <STRONG>curses</STRONG> window background
+ <B>bkgdset</B>, <B>wbkgdset</B>, <B>bkgd</B>, <B>wbkgd</B>, <B>getbkgd</B> - <B>curses</B> window background
manipulation routines
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
- <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
+ <B>#include</B> <B><curses.h></B>
- <STRONG>void</STRONG> <STRONG>bkgdset(chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
- <STRONG>void</STRONG> <STRONG>wbkgdset(WINDOW</STRONG> <STRONG>*</STRONG><EM>win,</EM> <EM>chtype</EM> <EM>ch</EM><STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>bkgd(chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>wbkgd(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>chtype</STRONG> <EM>ch</EM><STRONG>);</STRONG>
- <STRONG>chtype</STRONG> <STRONG>getbkgd(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
+ <B>void</B> <B>bkgdset(chtype</B> <I>ch</I><B>);</B>
+ <B>void</B> <B>wbkgdset(WINDOW</B> <B>*</B><I>win,</I> <I>chtype</I> <I>ch</I><B>);</B>
+
+ <B>int</B> <B>bkgd(chtype</B> <I>ch</I><B>);</B>
+ <B>int</B> <B>wbkgd(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>chtype</B> <I>ch</I><B>);</B>
+
+ <B>chtype</B> <B>getbkgd(WINDOW</B> <B>*</B><I>win</I><B>);</B>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
</PRE><H3><a name="h3-bkgdset">bkgdset</a></H3><PRE>
- The <STRONG>bkgdset</STRONG> and <STRONG>wbkgdset</STRONG> routines manipulate the background of the
- named window. The window background is a <STRONG>chtype</STRONG> consisting of any com-
- bination of attributes (i.e., rendition) and a character. The
+ The <B>bkgdset</B> and <B>wbkgdset</B> routines manipulate the background of the
+ named window. The window background is a <B>chtype</B> consisting of any
+ combination of attributes (i.e., rendition) and a character. The
attribute part of the background is combined (OR'ed) with all non-blank
- characters that are written into the window with <STRONG>waddch</STRONG>. Both the
+ characters that are written into the window with <B>waddch</B>. Both the
character and attribute parts of the background are combined with the
blank characters. The background becomes a property of the character
and moves with the character through any scrolling and insert/delete
</PRE><H3><a name="h3-bkgd">bkgd</a></H3><PRE>
- The <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> functions set the background property of the current
+ The <B>bkgd</B> and <B>wbkgd</B> functions set the background property of the current
or specified window and then apply this setting to every character
position in that window. According to X/Open Curses, it should do
this:
- <STRONG>o</STRONG> The rendition of every character on the screen is changed to the
+ <B>o</B> The rendition of every character on the screen is changed to the
new background rendition.
- <STRONG>o</STRONG> Wherever the former background character appears, it is changed to
+ <B>o</B> Wherever the former background character appears, it is changed to
the new background character.
Neither X/Open Curses nor the SVr4 manual pages give details about the
- way the rendition of characters on the screen is updated when <STRONG>bkgd</STRONG> or
- <STRONG>wbkgd</STRONG> is used to change the background character.
+ way the rendition of characters on the screen is updated when <B>bkgd</B> or
+ <B>wbkgd</B> is used to change the background character.
This implementation, like SVr4 curses, does not store the background
and window attribute contributions to each cell separately. It updates
- the rendition by comparing the character, non-color attributes and col-
- ors contained in the background. For each cell in the window, whether
- or not it is blank:
+ the rendition by comparing the character, non-color attributes and
+ colors contained in the background. For each cell in the window,
+ whether or not it is blank:
- <STRONG>o</STRONG> The library first compares the <EM>character</EM>, and if it matches the
+ <B>o</B> The library first compares the <I>character</I>, and if it matches the
current character part of the background, it replaces that with the
new background character.
- <STRONG>o</STRONG> The library then checks if the cell uses color, i.e., its color
+ <B>o</B> The library then checks if the cell uses color, i.e., its color
pair value is nonzero. If not, it simply replaces the attributes
- and color pair in the cell with those from the new background char-
- acter.
+ and color pair in the cell with those from the new background
+ character.
- <STRONG>o</STRONG> If the cell uses color, and that matches the color in the current
+ <B>o</B> If the cell uses color, and that matches the color in the current
background, the library removes attributes which may have come from
the current background and adds attributes from the new background.
- It finishes by setting the cell to use the color from the new back-
- ground.
+ It finishes by setting the cell to use the color from the new
+ background.
- <STRONG>o</STRONG> If the cell uses color, and that does not match the color in the
+ <B>o</B> If the cell uses color, and that does not match the color in the
current background, the library updates only the non-color
- attributes, first removing those which may have come from the cur-
- rent background, and then adding attributes from the new back-
- ground.
+ attributes, first removing those which may have come from the
+ current background, and then adding attributes from the new
+ background.
+
+ If the background's character value is zero, a space is assumed.
+
+ If the terminal does not support color, or if color has not been
+ started with <B>start_color</B>, the new background character's color
+ attribute will be ignored.
</PRE><H3><a name="h3-getbkgd">getbkgd</a></H3><PRE>
- The <STRONG>getbkgd</STRONG> function returns the given window's current background
+ The <B>getbkgd</B> function returns the given window's current background
character/attribute pair.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
These functions are described in the XSI Curses standard, Issue 4. It
- specifies that <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> return <STRONG>ERR</STRONG> on failure, but gives no fail-
- ure conditions.
+ specifies that <B>bkgd</B> and <B>wbkgd</B> return <B>ERR</B> on failure, but gives no
+ failure conditions.
- The routines <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> return the integer <STRONG>OK</STRONG>, unless the library
+ The routines <B>bkgd</B> and <B>wbkgd</B> return the integer <B>OK</B>, unless the library
has not been initialized.
- In contrast, the SVr4.0 manual says <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> may return <STRONG>OK</STRONG> "or a
- non-negative integer if <STRONG>immedok</STRONG> is set", which refers to the return
- value from <STRONG>wrefresh</STRONG> (used to implement the immediate repainting). The
- SVr4 curses <STRONG>wrefresh</STRONG> returns the number of characters written to the
+ In contrast, the SVr4.0 manual says <B>bkgd</B> and <B>wbkgd</B> may return <B>OK</B> "or a
+ non-negative integer if <B>immedok</B> is set", which refers to the return
+ value from <B>wrefresh</B> (used to implement the immediate repainting). The
+ SVr4 curses <B>wrefresh</B> returns the number of characters written to the
screen during the refresh. This implementation does not do that.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
- Note that <STRONG>bkgdset</STRONG> and <STRONG>bkgd</STRONG> may be macros.
+ Note that <B>bkgdset</B> and <B>bkgd</B> may be macros.
X/Open Curses mentions that the character part of the background must
be a single-byte value. This implementation, like SVr4, checks to
</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_addch.3x.html">curs_addch(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_addch.3X.html">curs_addch(3X)</A></B>, <B><A HREF="curs_attr.3X.html">curs_attr(3X)</A></B>, <B><A HREF="curs_outopts.3X.html">curs_outopts(3X)</A></B>
- <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>
+ <B><A HREF="curs_bkgd.3X.html">curs_bkgd(3X)</A></B>
</PRE>
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