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+ * Copyright 2019,2020 Thomas E. Dickey *
+ * Copyright 2001-2015,2017 Free Software Foundation, Inc. *
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- * @Id: curs_add_wch.3x,v 1.24 2017/11/18 23:47:37 tom Exp @
+ * @Id: curs_add_wch.3x,v 1.28 2020/10/17 23:10:38 tom Exp @
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-<H1 class="no-header">curs_add_wch 3x</H1>
+<H1 class="no-header">curs_add_wch 3X</H1>
<PRE>
-<STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG> <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
+<B><A HREF="curs_add_wch.3X.html">curs_add_wch(3X)</A></B> <B><A HREF="curs_add_wch.3X.html">curs_add_wch(3X)</A></B>
</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
+ <B>add_wch</B>, <B>wadd_wch</B>, <B>mvadd_wch</B>, <B>mvwadd_wch</B>, <B>echo_wchar</B>, <B>wecho_wchar</B> - add
+ a complex character and rendition to a <B>curses</B> window, then advance the
cursor
</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>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>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>
+ <B>int</B> <B>add_wch(</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
+ <B>int</B> <B>wadd_wch(</B> <B>WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
+ <B>int</B> <B>mvadd_wch(</B> <B>int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
+ <B>int</B> <B>mvwadd_wch(</B> <B>WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
+
+ <B>int</B> <B>echo_wchar(</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
+ <B>int</B> <B>wecho_wchar(</B> <B>WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>const</B> <B>cchar_t</B> <B>*</B><I>wch</I> <B>);</B>
</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 com-
- plex character <EM>wch</EM> into the given window at its current position, which
- is then advanced. These functions perform wrapping and special-charac-
- ter 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 cur-
- sor then advances to the next spacing 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 spec-
- ified by <EM>wch</EM> is ignored.
-
- <STRONG>o</STRONG> If the character part of <EM>wch</EM> is a tab, newline, backspace or other
+ The <B>add_wch</B>, <B>wadd_wch</B>, <B>mvadd_wch</B>, and <B>mvwadd_wch</B> functions put the
+ complex character <I>wch</I> into the given window at its current position,
+ which is then advanced. These functions perform wrapping and special-
+ character processing as follows:
+
+ <B>o</B> If <I>wch</I> refers to a spacing character, then any previous character
+ at that location is removed. A new character specified by <I>wch</I> is
+ placed at that location with rendition specified by <I>wch</I>. The
+ cursor then advances to the next spacing character on the screen.
+
+ <B>o</B> If <I>wch</I> refers to a non-spacing character, all previous characters
+ at that location are preserved. The non-spacing characters of <I>wch</I>
+ are added to the spacing complex character, and the rendition
+ specified by <I>wch</I> is ignored.
+
+ <B>o</B> If the character part of <I>wch</I> is a tab, newline, backspace or other
control character, the window is updated and the cursor moves as if
- <STRONG>addch</STRONG> were called.
+ <B>addch</B> were called.
</PRE><H3><a name="h3-echo_wchar">echo_wchar</a></H3><PRE>
- The <STRONG>echo_wchar</STRONG> function is functionally equivalent to a call to <STRONG>add_wch</STRONG>
- followed by a call to <STRONG><A HREF="curs_refresh.3x.html">refresh(3x)</A></STRONG>. Similarly, the <STRONG>wecho_wchar</STRONG> is func-
- tionally equivalent to a call to <STRONG>wadd_wch</STRONG> followed by a call to <STRONG>wre-</STRONG>
- <STRONG>fresh</STRONG>. The knowledge that only a single character is being output is
- taken into consideration and, for non-control characters, a consider-
- able performance gain might be seen by using the *<STRONG>echo</STRONG>* functions
- instead of their equivalents.
+ The <B>echo_wchar</B> function is functionally equivalent to a call to <B>add_wch</B>
+ followed by a call to <B><A HREF="curs_refresh.3X.html">refresh(3X)</A></B>. Similarly, the <B>wecho_wchar</B> is
+ functionally equivalent to a call to <B>wadd_wch</B> followed by a call to
+ <B>wrefresh</B>. The knowledge that only a single character is being output
+ is taken into consideration and, for non-control characters, a
+ considerable performance gain might be seen by using the *<B>echo</B>*
+ functions instead of their equivalents.
</PRE><H3><a name="h3-Line-Graphics">Line Graphics</a></H3><PRE>
- Like <STRONG><A HREF="curs_addch.3x.html">addch(3x)</A></STRONG>, <STRONG>addch_wch</STRONG> accepts symbols which make it simple to draw
- lines and other frequently used special characters. These symbols cor-
- respond to the same VT100 line-drawing set as <STRONG><A HREF="curs_addch.3x.html">addch(3x)</A></STRONG>.
+ Like <B><A HREF="curs_addch.3X.html">addch(3X)</A></B>, <B>addch_wch</B> accepts symbols which make it simple to draw
+ lines and other frequently used special characters. These symbols
+ correspond to the same VT100 line-drawing set as <B><A HREF="curs_addch.3X.html">addch(3X)</A></B>.
- <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>
+ <B>ACS</B> <B>Unicode</B> <B>ASCII</B> <B>acsc</B> <B>Glyph</B>
+ <B>Name</B> <B>Default</B> <B>Default</B> <B>char</B> <B>Name</B>
------------------------------------------------------------------------
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_DIAMOND 0x25c6 + ` diamond
WACS_GEQUAL 0x2265 > > greater-than-or-equal-to
WACS_HLINE 0x2500 - q horizontal line
WACS_LANTERN 0x2603 # i lantern symbol
WACS_VLINE 0x2502 | x vertical line
The wide-character configuration of ncurses also defines symbols for
- double-lines:
+ thick lines (<B>acsc</B> "J" to "V"):
- <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>
+ <B>ACS</B> <B>Unicode</B> <B>ASCII</B> <B>acsc</B> <B>Glyph</B>
+ <B>Name</B> <B>Default</B> <B>Default</B> <B>char</B> <B>Name</B>
+ -----------------------------------------------------------------------
+ WACS_T_BTEE 0x253b + V thick tee pointing up
+ WACS_T_HLINE 0x2501 - Q thick horizontal line
+ WACS_T_LLCORNER 0x2517 + M thick lower left corner
+ WACS_T_LRCORNER 0x251b + J thick lower right corner
+ WACS_T_LTEE 0x252b + T thick tee pointing right
+ WACS_T_PLUS 0x254b + N thick large plus
+ WACS_T_RTEE 0x2523 + U thick tee pointing left
+ WACS_T_TTEE 0x2533 + W thick tee pointing down
+ WACS_T_ULCORNER 0x250f + L thick upper left corner
+ WACS_T_URCORNER 0x2513 + K thick upper right corner
+ WACS_T_VLINE 0x2503 | X thick vertical line
+
+ and for double-lines (<B>acsc</B> "A" to "I"):
+
+ <B>ACS</B> <B>Unicode</B> <B>ASCII</B> <B>acsc</B> <B>Glyph</B>
+ <B>Name</B> <B>Default</B> <B>Default</B> <B>char</B> <B>Name</B>
------------------------------------------------------------------------
WACS_D_BTEE 0x2569 + H double tee pointing up
WACS_D_HLINE 0x2550 - R double horizontal line
WACS_D_URCORNER 0x2557 + B double upper right corner
WACS_D_VLINE 0x2551 | Y double vertical line
- and for thick lines:
+ Unicode's descriptions for these characters differs slightly from
+ ncurses, by introducing the term "light" (along with less important
+ details). Here are its descriptions for the normal, thick, and double
+ horizontal lines:
- <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_T_BTEE 0x253b + V thick tee pointing up
- WACS_T_HLINE 0x2501 - Q thick horizontal line
- WACS_T_LLCORNER 0x2517 + M thick lower left corner
- WACS_T_LRCORNER 0x251b + J thick lower right corner
- WACS_T_LTEE 0x252b + T thick tee pointing right
- WACS_T_PLUS 0x254b + N thick large plus
- WACS_T_RTEE 0x2523 + U thick tee pointing left
- WACS_T_TTEE 0x2533 + W thick tee pointing down
- WACS_T_ULCORNER 0x250f + L thick upper left corner
- WACS_T_URCORNER 0x2513 + K thick upper right corner
- WACS_T_VLINE 0x2503 | X thick vertical line
+ <B>o</B> U+2500 BOX DRAWINGS LIGHT HORIZONTAL
+
+ <B>o</B> U+2501 BOX DRAWINGS HEAVY HORIZONTAL
+
+ <B>o</B> U+2550 BOX DRAWINGS DOUBLE HORIZONTAL
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- All routines return the integer <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> on success.
+ All routines return the integer <B>ERR</B> upon failure and <B>OK</B> on success.
+
+ X/Open does not define any error conditions. This implementation
+ returns an error
+
+ <B>o</B> if the window pointer is null or
+
+ <B>o</B> if it is not possible to add a complete character in the window.
+
+ The latter may be due to different causes:
+
+ <B>o</B> If <B>scrollok</B> 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
+
+ <B>o</B> 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
+ resulting bytes in the window, an error is returned.
Functions with a "mv" prefix first perform a cursor movement using
- <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
+ <B>wmove</B>, and return an error if the position is outside the window, or if
the window pointer is null.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
- Note that <STRONG>add_wch</STRONG>, <STRONG>mvadd_wch</STRONG>, <STRONG>mvwadd_wch</STRONG>, and <STRONG>echo_wchar</STRONG> may be macros.
+ Note that <B>add_wch</B>, <B>mvadd_wch</B>, <B>mvwadd_wch</B>, and <B>echo_wchar</B> may be macros.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
POSIX locale.
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
+ as a pointer to <B>cchar_t</B> data, e.g., in the discussion of <B>border_set</B>. 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>.
+ <B>o</B> NetBSD curses defines the symbols as a <B>wchar_t</B> within a <B>cchar_t</B>.
- <STRONG>o</STRONG> HPUX curses equates some of the <EM>ACS</EM><STRONG>_</STRONG> symbols to the analogous <EM>WACS</EM><STRONG>_</STRONG>
- symbols as if the <EM>ACS</EM><STRONG>_</STRONG> symbols were wide characters. The misde-
- fined symbols are the arrows and other symbols which are not used
- for line-drawing.
+ <B>o</B> HPUX curses equates some of the <I>ACS</I><B>_</B> symbols to the analogous <I>WACS</I><B>_</B>
+ symbols as if the <I>ACS</I><B>_</B> symbols were wide characters. The
+ misdefined symbols are the arrows and other symbols which are not
+ used for line-drawing.
X/Open Curses does not define symbols for thick- or double-lines. SVr4
curses implementations defined their line-drawing symbols in terms of
- intermediate symbols. This implementation extends those symbols, pro-
- viding new definitions which are not in the SVr4 implementations.
+ intermediate symbols. This implementation extends those symbols,
+ providing new definitions which are not in the SVr4 implementations.
Not all Unicode-capable terminals provide support for VT100-style
- alternate character sets (i.e., the <STRONG>acsc</STRONG> capability), with their corre-
- sponding 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 the <STRONG>acsc</STRONG>
- character-mapping to provide this feature. As a result, those imple-
- mentations can only use single-byte line-drawing characters. Ncurses
- 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 ter-
- minal 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
+ alternate character sets (i.e., the <B>acsc</B> 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
+ the <B>acsc</B> 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
+ problems. NetBSD curses incorporated that table in 2010.
+
+ In this implementation, the Unicode values are used instead of the
+ terminal description's <B>acsc</B> mapping as discussed in <B><A HREF="ncurses.3X.html">ncurses(3X)</A></B> for the
+ environment variable <B>NCURSES_NO_UTF8_ACS</B>. In contrast, for the same
+ cases, the line-drawing characters described in <B><A HREF="curs_addch.3X.html">curs_addch(3X)</A></B> will use
only the ASCII default values.
Having Unicode available does not solve all of the problems with line-
drawing for curses:
- <STRONG>o</STRONG> The closest Unicode equivalents to the VT100 graphics <EM>S1</EM>, <EM>S3</EM>, <EM>S7</EM>
- and <EM>S9</EM> frequently are not displayed at the regular intervals which
+ <B>o</B> The closest Unicode equivalents to the VT100 graphics <I>S1</I>, <I>S3</I>, <I>S7</I>
+ and <I>S9</I> frequently are not displayed at the regular intervals which
the terminal used.
- <STRONG>o</STRONG> The <EM>lantern</EM> is a special case. It originated with the AT&T 4410
+ <B>o</B> The <I>lantern</I> is a special case. It originated with the AT&T 4410
terminal in the early 1980s. There is no accessible documentation
depicting the lantern symbol on the AT&T terminal.
- Lacking documentation, most readers assume that a <EM>storm</EM> <EM>lantern</EM> was
+ Lacking documentation, most readers assume that a <I>storm</I> <I>lantern</I> was
intended. But there are several possibilities, all with problems.
Unicode 6.0 (2010) does provide two lantern symbols: U+1F383 and
since they lie outside the BMP and as a result are not generally
available in terminals. They are not storm lanterns, in any case.
- Most <EM>storm</EM> <EM>lanterns</EM> have a tapering glass chimney (to guard against
+ Most <I>storm</I> <I>lanterns</I> have a tapering glass chimney (to guard against
tipping); some have a wire grid protecting the chimney.
For the tapering appearance, U+2603 was adequate. In use on a
terminal, no one can tell what the image represents. Unicode calls
it a snowman.
- Others have suggested these alternatives: S U+00A7 (section mark),
- <STRONG>O</STRONG> U+0398 (theta), <STRONG>O</STRONG> U+03A6 (phi), d U+03B4 (delta), U+2327 (x in a
- rectangle), U+256C (forms double vertical and horizontal), and
- U+2612 (ballot box with x).
+ Others have suggested these alternatives: <section> U+00A7 (section
+ mark), <Theta> U+0398 (theta), <Phi> U+03A6 (phi), <delta> U+03B4
+ (delta), U+2327 (x in a rectangle), U+256C (forms double vertical
+ and horizontal), and U+2612 (ballot box with x).
</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>curs_out-</STRONG>
- <STRONG><A HREF="curs_outopts.3x.html">opts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG>putwc(3)</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_clear.3X.html">curs_clear(3X)</A></B>,
+ <B><A HREF="curs_outopts.3X.html">curs_outopts(3X)</A></B>, <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>, <B>putwc(3)</B>
- <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>
+ <B><A HREF="curs_add_wch.3X.html">curs_add_wch(3X)</A></B>
</PRE>
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