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- * @Id: curs_add_wch.3x,v 1.33 2023/03/11 20:40:45 tom Exp @
+ * @Id: curs_add_wch.3x,v 1.50 2023/12/23 16:08:25 tom Exp @
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-<H1 class="no-header">curs_add_wch 3x 2023-03-11 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_add_wch 3x 2023-12-23 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
<STRONG>add_wch</STRONG>, <STRONG>wadd_wch</STRONG>, <STRONG>mvadd_wch</STRONG>, <STRONG>mvwadd_wch</STRONG>, <STRONG>echo_wchar</STRONG>, <STRONG>wecho_wchar</STRONG> - add
- a complex character and rendition to a <STRONG>curses</STRONG> window, then advance the
- cursor
+ a <EM>curses</EM> complex character to a window and advance the cursor
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
- <STRONG>int</STRONG> <STRONG>add_wch(</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>wadd_wch(</STRONG> <STRONG>WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>mvadd_wch(</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>mvwadd_wch(</STRONG> <STRONG>WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>add_wch(const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wadd_wch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>mvadd_wch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>mvwadd_wch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>echo_wchar(</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>wecho_wchar(</STRONG> <STRONG>WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM> <STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>echo_wchar(const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wecho_wchar(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>cchar_t</STRONG> <STRONG>*</STRONG><EM>wch</EM><STRONG>);</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
</PRE><H3><a name="h3-add_wch">add_wch</a></H3><PRE>
- The <STRONG>add_wch</STRONG>, <STRONG>wadd_wch</STRONG>, <STRONG>mvadd_wch</STRONG>, and <STRONG>mvwadd_wch</STRONG> functions put the
- complex character <EM>wch</EM> into the given window at its current position,
- which is then advanced. These functions perform wrapping and special-
+ The <STRONG>add_wch</STRONG>, <STRONG>wadd_wch</STRONG>, <STRONG>mvadd_wch</STRONG>, and <STRONG>mvwadd_wch</STRONG> functions put the
+ complex character <EM>wch</EM> into the given window at its current position,
+ which is then advanced. These functions perform wrapping and special-
character processing as follows:
- <STRONG>o</STRONG> If <EM>wch</EM> refers to a spacing character, then any previous character
- at that location is removed. A new character specified by <EM>wch</EM> is
- placed at that location with rendition specified by <EM>wch</EM>. The
- cursor then advances to the next spacing character on the screen.
+ <STRONG>o</STRONG> If <EM>wch</EM> refers to a spacing character, then any previous character
+ at that location is removed. A new character specified by <EM>wch</EM> is
+ placed at that location with rendition specified by <EM>wch</EM>. The
+ cursor then advances after this spacing character, to prepare for
+ writing the next character on the screen.
- <STRONG>o</STRONG> If <EM>wch</EM> refers to a non-spacing character, all previous characters
- at that location are preserved. The non-spacing characters of <EM>wch</EM>
- are added to the spacing complex character, and the rendition
- specified by <EM>wch</EM> is ignored.
+ The newly added spacing character is the base of the active complex
+ character. Subsequent non-spacing characters can be combined with
+ this base until another spacing character is written to the screen,
+ or the cursor is moved, e.g., using <STRONG>wmove</STRONG>.
+
+ <STRONG>o</STRONG> If <EM>wch</EM> refers to a non-spacing character, it is appended to the
+ active complex character, retaining the previous characters at that
+ location. The rendition specified by <EM>wch</EM> is ignored.
+
+ The cursor is not advanced after adding a non-spacing character.
+ Subsequent calls to add non-spacing characters will update the same
+ position.
<STRONG>o</STRONG> If the character part of <EM>wch</EM> is a tab, newline, backspace or other
control character, the window is updated and the cursor moves as if
<STRONG>ACS</STRONG> <STRONG>Unicode</STRONG> <STRONG>ASCII</STRONG> <STRONG>acsc</STRONG> <STRONG>Glyph</STRONG>
<STRONG>Name</STRONG> <STRONG>Default</STRONG> <STRONG>Default</STRONG> <STRONG>char</STRONG> <STRONG>Name</STRONG>
+
------------------------------------------------------------------------
WACS_BLOCK 0x25ae # 0 solid square block
WACS_BOARD 0x2592 # h board of squares
WACS_CKBOARD 0x2592 : a checker board (stipple)
WACS_DARROW 0x2193 v . arrow pointing down
WACS_DEGREE 0x00b0 ' f degree symbol
-
WACS_DIAMOND 0x25c6 + ` diamond
WACS_GEQUAL 0x2265 > > greater-than-or-equal-to
WACS_HLINE 0x2500 - q horizontal line
WACS_URCORNER 0x2510 + k upper right-hand corner
WACS_VLINE 0x2502 | x vertical line
- The wide-character configuration of ncurses also defines symbols for
+ The wide-character configuration of <EM>ncurses</EM> also defines symbols for
thick lines (<STRONG>acsc</STRONG> "J" to "V"):
<STRONG>ACS</STRONG> <STRONG>Unicode</STRONG> <STRONG>ASCII</STRONG> <STRONG>acsc</STRONG> <STRONG>Glyph</STRONG>
WACS_D_PLUS 0x256c + E double large plus
WACS_D_RTEE 0x2563 + G double tee pointing left
WACS_D_TTEE 0x2566 + I double tee pointing down
+
WACS_D_ULCORNER 0x2554 + C double upper left corner
WACS_D_URCORNER 0x2557 + B double upper right corner
WACS_D_VLINE 0x2551 | Y double vertical line
Unicode's descriptions for these characters differs slightly from
- ncurses, by introducing the term "light" (along with less important
+ <EM>ncurses</EM>, by introducing the term "light" (along with less important
details). Here are its descriptions for the normal, thick, and double
horizontal lines:
<STRONG>o</STRONG> If <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG> is not enabled, writing a character at the lower
right margin succeeds. However, an error is returned because it is
- not possible to wrap to a new line
+ not possible to wrap to a new line.
<STRONG>o</STRONG> If an error is detected when converting a multibyte character to a
sequence of bytes, or if it is not possible to add all of the
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- All of these functions are described in the XSI Curses standard, Issue
- 4. The defaults specified for line-drawing characters apply in the
- POSIX locale.
+ These functions are described in the XSI Curses standard, Issue 4. The
+ defaults specified for line-drawing characters apply in the POSIX
+ locale.
+
+</PRE><H3><a name="h3-WACS-Symbols">WACS Symbols</a></H3><PRE>
X/Open Curses makes it clear that the WACS_ symbols should be defined
as a pointer to <STRONG>cchar_t</STRONG> data, e.g., in the discussion of <STRONG>border_set</STRONG>. A
few implementations are problematic:
<STRONG>o</STRONG> NetBSD curses defines the symbols as a <STRONG>wchar_t</STRONG> within a <STRONG>cchar_t</STRONG>.
- <STRONG>o</STRONG> HPUX curses equates some of the <STRONG>ACS_</STRONG> symbols to the analogous <STRONG>WACS_</STRONG>
- symbols as if the <STRONG>ACS_</STRONG> symbols were wide characters. The
+ <STRONG>o</STRONG> HP-UX curses equates some of the <STRONG>ACS_</STRONG> symbols to the analogous
+ <STRONG>WACS_</STRONG> symbols as if the <STRONG>ACS_</STRONG> symbols were wide characters. The
misdefined symbols are the arrows and other symbols which are not
used for line-drawing.
alternate character sets (i.e., the <STRONG>acsc</STRONG> capability), with their
corresponding line-drawing characters. X/Open Curses did not address
the aspect of integrating Unicode with line-drawing characters.
- Existing implementations of Unix curses (AIX, HPUX, Solaris) use only
+ Existing implementations of Unix curses (AIX, HP-UX, Solaris) use only
the <STRONG>acsc</STRONG> character-mapping to provide this feature. As a result, those
implementations can only use single-byte line-drawing characters.
- Ncurses 5.3 (2002) provided a table of Unicode values to solve these
+ <EM>ncurses</EM> 5.3 (2002) provided a table of Unicode values to solve these
problems. NetBSD curses incorporated that table in 2010.
In this implementation, the Unicode values are used instead of the
terminal description's <STRONG>acsc</STRONG> mapping as discussed in <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG> for the
- environment variable <STRONG>NCURSES_NO_UTF8_ACS</STRONG>. In contrast, for the same
- cases, the line-drawing characters described in <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG> will use
- only the ASCII default values.
+ environment variable <EM>NCURSES</EM><STRONG>_</STRONG><EM>NO</EM><STRONG>_</STRONG><EM>UTF8</EM><STRONG>_</STRONG><EM>ACS</EM>. In contrast, for the same
+ cases, the line-drawing characters described in <STRONG><A HREF="curs_addch.3x.html">addch(3x)</A></STRONG> will use only
+ the ASCII default values.
Having Unicode available does not solve all of the problems with line-
drawing for curses:
and horizontal), and U+2612 (ballot box with x).
+</PRE><H3><a name="h3-Complex-Characters">Complex Characters</a></H3><PRE>
+ The complex character type <STRONG>cchar_t</STRONG> can store more than one wide
+ character (<STRONG>wchar_t</STRONG>). The X/Open Curses description does not mention
+ this possibility, describing only the cases where <EM>wch</EM> is a spacing
+ character or a non-spacing character.
+
+ This implementation assumes that <EM>wch</EM> is constructed using <STRONG><A HREF="curs_getcchar.3x.html">setcchar(3x)</A></STRONG>,
+ and in turn that the result
+
+ <STRONG>o</STRONG> contains at most one spacing character in the beginning of its list
+ of wide characters, and zero or more non-spacing characters or
+
+ <STRONG>o</STRONG> may hold one non-spacing character.
+
+ In the latter case, <EM>ncurses</EM> adds the non-spacing character to the
+ active (base) spacing character.
+
+
</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_clear.3x.html">curs_clear(3x)</A></STRONG>,
- <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG>putwc(3)</STRONG>
+ <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_clear.3x.html">curs_clear(3x)</A></STRONG>,
+ <STRONG><A HREF="curs_getcchar.3x.html">curs_getcchar(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG>putwc(3)</STRONG>
-ncurses 6.4 2023-03-11 <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
+ncurses 6.4 2023-12-23 <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
</PRE>
<div class="nav">
<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-PORTABILITY">PORTABILITY</a>
+<ul>
+<li><a href="#h3-WACS-Symbols">WACS Symbols</a></li>
+<li><a href="#h3-Complex-Characters">Complex Characters</a></li>
+</ul>
+</li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
</ul>
</div>