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- * @Id: curs_attr.3x,v 1.61 2017/11/18 23:47:37 tom Exp @
+ * @Id: curs_attr.3x,v 1.87 2023/10/07 22:21:46 tom Exp @
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-<H1 class="no-header">curs_attr 3x</H1>
+<H1 class="no-header">curs_attr 3x 2023-10-07 ncurses 6.4 Library calls</H1>
<PRE>
-<STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
<STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
+<STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
Library calls <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
<STRONG>attr_get</STRONG>, <STRONG>wattr_get</STRONG>, <STRONG>attr_set</STRONG>, <STRONG>wattr_set</STRONG>, <STRONG>attr_off</STRONG>, <STRONG>wattr_off</STRONG>, <STRONG>attr_on</STRONG>,
<STRONG>wattr_on</STRONG>, <STRONG>attroff</STRONG>, <STRONG>wattroff</STRONG>, <STRONG>attron</STRONG>, <STRONG>wattron</STRONG>, <STRONG>attrset</STRONG>, <STRONG>wattrset</STRONG>, <STRONG>chgat</STRONG>,
- <STRONG>wchgat</STRONG>, <STRONG>mvchgat</STRONG>, <STRONG>mvwchgat</STRONG>, <STRONG>color_set</STRONG>, <STRONG>wcolor_set</STRONG>, <STRONG>standend</STRONG>, <STRONG>wstandend</STRONG>,
- <STRONG>standout</STRONG>, <STRONG>wstandout</STRONG> - <STRONG>curses</STRONG> character and window attribute control
- routines
+ <STRONG>wchgat</STRONG>, <STRONG>mvchgat</STRONG>, <STRONG>mvwchgat</STRONG>, <STRONG>color_set</STRONG>, <STRONG>wcolor_set</STRONG>, <STRONG>standend</STRONG>, <STRONG>wstandend</STRONG>,
+ <STRONG>standout</STRONG>, <STRONG>wstandout</STRONG> - manipulate attributes of character cells in
+ <EM>curses</EM> windows
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>int</STRONG> <STRONG>attr_on(attr_t</STRONG> <EM>attrs</EM><STRONG>,</STRONG> <STRONG>void</STRONG> <STRONG>*</STRONG><EM>opts</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>wattr_on(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>attr_t</STRONG> <EM>attrs</EM><STRONG>,</STRONG> <STRONG>void</STRONG> <STRONG>*</STRONG><EM>opts</EM><STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>attroff(int</STRONG> <EM>attrs);</EM>
+ <STRONG>int</STRONG> <STRONG>attroff(int</STRONG> <EM>attrs</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>wattroff(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>attrs</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>attron(int</STRONG> <EM>attrs</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>wattron(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>attrs</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <EM>n,</EM> <STRONG>attr_t</STRONG> <EM>attr</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*</STRONG><EM>opts</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>color_set(short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>void*</STRONG> <EM>opts</EM><STRONG>);</STRONG>
- <STRONG>int</STRONG> <STRONG>wcolor_set(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>void*</STRONG> <EM>opts);</EM>
+ <STRONG>int</STRONG> <STRONG>wcolor_set(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>void*</STRONG> <EM>opts</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>standend(void);</STRONG>
<STRONG>int</STRONG> <STRONG>wstandend(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
These routines manipulate the current attributes of the named window,
which then apply to all characters that are written into the window
with <STRONG>waddch</STRONG>, <STRONG>waddstr</STRONG> and <STRONG>wprintw</STRONG>. Attributes are a property of the
- character, and move with the character through any scrolling and in-
- sert/delete line/character operations. To the extent possible, they
+ character, and move with the character through any scrolling and
+ insert/delete line/character operations. To the extent possible, they
are displayed as appropriate modifications to the graphic rendition of
characters put on the screen.
These routines do not affect the attributes used when erasing portions
- of the window. See <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG> for functions which modify the at-
- tributes used for erasing and clearing.
+ of the window. See <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG> for functions which modify the
+ attributes used for erasing and clearing.
Routines which do not have a <STRONG>WINDOW*</STRONG> parameter apply to <STRONG>stdscr</STRONG>. For
example, <STRONG>attr_set</STRONG> is the <STRONG>stdscr</STRONG> variant of <STRONG>wattr_set</STRONG>.
</PRE><H3><a name="h3-Window-attributes">Window attributes</a></H3><PRE>
There are two sets of functions:
- <STRONG>o</STRONG> functions for manipulating the window attributes and color: <STRONG>wat-</STRONG>
- <STRONG>tr_set</STRONG> and <STRONG>wattr_get</STRONG>.
+ <STRONG>o</STRONG> functions for manipulating the window attributes and color:
+ <STRONG>wattr_set</STRONG> and <STRONG>wattr_get</STRONG>.
<STRONG>o</STRONG> functions for manipulating only the window attributes (not color):
<STRONG>wattr_on</STRONG> and <STRONG>wattr_off</STRONG>.
Use <STRONG>wattr_get</STRONG> to retrieve attributes for the given window.
Use <STRONG>attr_on</STRONG> and <STRONG>wattr_on</STRONG> to turn on window attributes, i.e., values
- OR'd together in <EM>attr</EM>, without affecting other attributes. Use <STRONG>at-</STRONG>
- <STRONG>tr_off</STRONG> and <STRONG>wattr_off</STRONG> to turn off window attributes, again values OR'd
+ OR'd together in <EM>attr</EM>, without affecting other attributes. Use
+ <STRONG>attr_off</STRONG> and <STRONG>wattr_off</STRONG> to turn off window attributes, again values OR'd
together in <EM>attr</EM>, without affecting other attributes.
</PRE><H3><a name="h3-Legacy-window-attributes">Legacy window attributes</a></H3><PRE>
- Most of the window attribute routines are extensions of older routines
- which assume that color pairs are OR'd into the attribute parameter.
- These older routines use the same name, omitting an underscore (<STRONG>_</STRONG>).
+ The X/Open window attribute routines which <EM>set</EM> or <EM>get</EM>, turn <EM>on</EM> or <EM>off</EM>
+ are extensions of older routines which assume that color pairs are OR'd
+ into the attribute parameter. These newer routines use similar names,
+ because X/Open simply added an underscore (<STRONG>_</STRONG>) for the newer names.
+
+ The <STRONG>int</STRONG> datatype used in the legacy routines is treated as if it is the
+ same size as <STRONG>chtype</STRONG> (used by <STRONG><A HREF="curs_addch.3x.html">addch(3x)</A></STRONG>). It holds the common video
+ attributes (such as bold, reverse), as well as a few bits for color.
+ Those bits correspond to the <STRONG>A_COLOR</STRONG> symbol. The <STRONG>COLOR_PAIR</STRONG> macro
+ provides a value which can be OR'd into the attribute parameter. For
+ example, as long as that value fits into the <STRONG>A_COLOR</STRONG> mask, then these
+ calls produce similar results:
+
+ attrset(A_BOLD | COLOR_PAIR(<EM>pair</EM>));
+ attr_set(A_BOLD, <EM>pair</EM>, NULL);
+
+ However, if the value does not fit, then the <STRONG>COLOR_PAIR</STRONG> macro uses only
+ the bits that fit. For example, because in ncurses <STRONG>A_COLOR</STRONG> has eight
+ (8) bits, then <STRONG>COLOR_PAIR(</STRONG><EM>259</EM><STRONG>)</STRONG> is 4 (i.e., 259 is 4 more than the limit
+ 255).
+
+ The <STRONG>PAIR_NUMBER</STRONG> macro extracts a pair number from an <STRONG>int</STRONG> (or <STRONG>chtype</STRONG>).
+ For example, the <EM>input</EM> and <EM>output</EM> values in these statements would be
+ the same:
+
+ int value = A_BOLD | COLOR_PAIR(<EM>input</EM>);
+ int <EM>output</EM> = PAIR_NUMBER(value);
The <STRONG>attrset</STRONG> routine is a legacy feature predating SVr4 curses but kept
- in X/Open Curses for the same reason that SVr4 curses kept it: compati-
- bility.
+ in X/Open Curses for the same reason that SVr4 curses kept it:
+ compatibility.
The remaining <STRONG>attr</STRONG>* functions operate exactly like the corresponding
<STRONG>attr_</STRONG>* functions, except that they take arguments of type <STRONG>int</STRONG> rather
</PRE><H3><a name="h3-Change-character-rendition">Change character rendition</a></H3><PRE>
- The routine <STRONG>chgat</STRONG> changes the attributes of a given number of charac-
- ters starting at the current cursor location of <STRONG>stdscr</STRONG>. It does not
- update the cursor and does not perform wrapping. A character count of
- -1 or greater than the remaining window width means to change at-
- tributes all the way to the end of the current line. The <STRONG>wchgat</STRONG> func-
- tion generalizes this to any window; the <STRONG>mvwchgat</STRONG> function does a cur-
- sor move before acting.
+ The routine <STRONG>chgat</STRONG> changes the attributes of a given number of
+ characters starting at the current cursor location of <STRONG>stdscr</STRONG>. It does
+ not update the cursor and does not perform wrapping. A character count
+ of -1 or greater than the remaining window width means to change
+ attributes all the way to the end of the current line. The <STRONG>wchgat</STRONG>
+ function generalizes this to any window; the <STRONG>mvwchgat</STRONG> function does a
+ cursor move before acting.
In these functions, the color <EM>pair</EM> argument is a color-pair index (as
in the first argument of <STRONG>init_pair</STRONG>, see <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>).
</PRE><H3><a name="h3-Change-window-color">Change window color</a></H3><PRE>
The routine <STRONG>color_set</STRONG> sets the current color of the given window to the
- foreground/background combination described by the color <EM>pair</EM> parame-
- ter.
+ foreground/background combination described by the color <EM>pair</EM>
+ parameter.
</PRE><H3><a name="h3-Standout">Standout</a></H3><PRE>
<STRONG>o</STRONG> they have well established legacy use, and
- <STRONG>o</STRONG> there is no ambiguity about the way the attributes might be com-
- bined with a color pair.
+ <STRONG>o</STRONG> there is no ambiguity about the way the attributes might be
+ combined with a color pair.
</PRE><H2><a name="h2-VIDEO-ATTRIBUTES">VIDEO ATTRIBUTES</a></H2><PRE>
the routines <STRONG>attron</STRONG>, <STRONG>attroff</STRONG>, and <STRONG>attrset</STRONG>, or OR'd with the characters
passed to <STRONG>addch</STRONG> (see <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>).
- <EM>Name</EM> <EM>Description</EM>
- -----------------------------------------------------------
+ <STRONG>Name</STRONG> <STRONG>Description</STRONG>
+ -----------------------------------------------------------------
<STRONG>A_NORMAL</STRONG> Normal display (no highlight)
<STRONG>A_STANDOUT</STRONG> Best highlighting mode of the terminal.
<STRONG>A_UNDERLINE</STRONG> Underlining
<STRONG>A_ALTCHARSET</STRONG> Alternate character set
<STRONG>A_ITALIC</STRONG> Italics (non-X/Open extension)
<STRONG>A_CHARTEXT</STRONG> Bit-mask to extract a character
+ <STRONG>A_COLOR</STRONG> Bit-mask to extract a color (legacy routines)
These video attributes are supported by <STRONG>attr_on</STRONG> and related functions
(which also support the attributes recognized by <STRONG>attron</STRONG>, etc.):
- <EM>Name</EM> <EM>Description</EM>
+ <STRONG>Name</STRONG> <STRONG>Description</STRONG>
-----------------------------------------
<STRONG>WA_HORIZONTAL</STRONG> Horizontal highlight
<STRONG>WA_LEFT</STRONG> Left highlight
</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
X/Open Curses is largely based on SVr4 curses, adding support for
- "wide-characters" (not specific to Unicode). Some of the X/Open dif-
- ferences from SVr4 curses address the way video attributes can be ap-
- plied to wide-characters. But aside from that, <STRONG>attrset</STRONG> and <STRONG>attr_set</STRONG>
+ "wide-characters" (not specific to Unicode). Some of the X/Open
+ differences from SVr4 curses address the way video attributes can be
+ applied to wide-characters. But aside from that, <STRONG>attrset</STRONG> and <STRONG>attr_set</STRONG>
are similar. SVr4 curses provided the basic features for manipulating
video attributes. However, earlier versions of curses provided a part
of these features.
<STRONG>standout</STRONG> and <STRONG>standend</STRONG> which were carried along into X/Open Curses due
to their pervasive use in legacy applications.
- Some terminals in the 1980s could support a variety of video at-
- tributes, although the BSD curses library could do nothing with those.
- System V (1983) provided an improved curses library. It defined the <STRONG>A_</STRONG>
- symbols for use by applications to manipulate the other attributes.
- There are few useful references for the chronology.
+ Some terminals in the 1980s could support a variety of video
+ attributes, although the BSD curses library could do nothing with
+ those. System V (1983) provided an improved curses library. It
+ defined the <STRONG>A_</STRONG> symbols for use by applications to manipulate the other
+ attributes. There are few useful references for the chronology.
Goodheart's book <EM>UNIX</EM> <EM>Curses</EM> <EM>Explained</EM> (1991) describes SVr3 (1987),
commenting on several functions:
This table showing the number of bits for <STRONG>A_COLOR</STRONG> and <STRONG>A_CHARTEXT</STRONG> was
gleaned from the curses header files for various operating systems and
architectures. The inferred architecture and notes reflect the format
- and size of the defined constants as well as clues such as the alter-
- nate character set implementation. A 32-bit library can be used on a
- 64-bit system, but not necessarily the reverse.
+ and size of the defined constants as well as clues such as the
+ alternate character set implementation. A 32-bit library can be used
+ on a 64-bit system, but not necessarily the reverse.
- <EM>Year</EM> <EM>System</EM> <EM>Arch</EM> <EM>Color</EM> <EM>Char</EM> <EM>Notes</EM>
+ <STRONG>Year</STRONG> <STRONG>System</STRONG> <STRONG>Arch</STRONG> <STRONG>Color</STRONG> <STRONG>Char</STRONG> <STRONG>Notes</STRONG>
----------------------------------------------------------------
1992 Solaris 5.2 32 6 17 SVr4 curses
1992 HPUX 9 32 no 8 SVr2 curses
1995 Solaris 5.4 32/64 7 16 X/Open curses
1996 AIX 4.2 32 7 16 X/Open curses
1996 OSF/1 r4 32 6 16 X/Open curses
+
1997 HP-UX 11.00 32 6 8 X/Open curses
2000 U/Win 32/64 7/31 16 uses <STRONG>chtype</STRONG>
Regarding OSF/1 (and Tru64),
- <STRONG>o</STRONG> These used 64-bit hardware. Like ncurses, the OSF/1 curses in-
- terface is not customized for 32-bit and 64-bit versions.
+ <STRONG>o</STRONG> These used 64-bit hardware. Like ncurses, the OSF/1 curses
+ interface is not customized for 32-bit and 64-bit versions.
- <STRONG>o</STRONG> Unlike other systems which evolved from AT&T code, OSF/1 provid-
- ed a new implementation for X/Open curses.
+ <STRONG>o</STRONG> Unlike other systems which evolved from AT&T code, OSF/1
+ provided a new implementation for X/Open curses.
Regarding Solaris,
Sun's copyright began in 1996.
<STRONG>o</STRONG> Sun updated the X/Open curses interface after 64-bit support was
- introduced in 1997, but did not modify the SVr4 curses inter-
- face.
+ introduced in 1997, but did not modify the SVr4 curses
+ interface.
Regarding U/Win,
Other interfaces are rarely used now:
<STRONG>o</STRONG> BSD curses was improved slightly in 1993/1994 using Keith Bostic's
- modification to make the library 8-bit clean for <STRONG>nvi</STRONG>. He moved
+ modification to make the library 8-bit clean for <STRONG>nvi(1)</STRONG>. He moved
<EM>standout</EM> attribute to a structure member.
The resulting 4.4BSD curses was replaced by ncurses over the next
</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
This implementation provides the <STRONG>A_ITALIC</STRONG> attribute for terminals which
- have the <STRONG>enter_italics_mode</STRONG> (<STRONG>sitm</STRONG>) and <STRONG>exit_italics_mode</STRONG> (<STRONG>ritm</STRONG>) capa-
- bilities. Italics are not mentioned in X/Open Curses. Unlike the oth-
- er video attributes, <STRONG>A_ITALIC</STRONG> is unrelated to the <STRONG>set_attributes</STRONG> capa-
- bilities. This implementation makes the assumption that <STRONG>exit_at-</STRONG>
- <STRONG>tribute_mode</STRONG> may also reset italics.
+ have the <STRONG>enter_italics_mode</STRONG> (<STRONG>sitm</STRONG>) and <STRONG>exit_italics_mode</STRONG> (<STRONG>ritm</STRONG>)
+ capabilities. Italics are not mentioned in X/Open Curses. Unlike the
+ other video attributes, <STRONG>A_ITALIC</STRONG> is unrelated to the <STRONG>set_attributes</STRONG>
+ capabilities. This implementation makes the assumption that
+ <STRONG>exit_attribute_mode</STRONG> may also reset italics.
Each of the functions added by XSI Curses has a parameter <EM>opts</EM>, which
- X/Open Curses still (after more than twenty years) documents as re-
- served for future use, saying that it should be <STRONG>NULL</STRONG>. This implementa-
- tion uses that parameter in ABI 6 for the functions which have a color-
- pair parameter to support <EM>extended</EM> <EM>color</EM> <EM>pairs</EM>:
+ X/Open Curses still (after more than twenty years) documents as
+ reserved for future use, saying that it should be <STRONG>NULL</STRONG>. This
+ implementation uses that parameter in ABI 6 for the functions which
+ have a color-pair parameter to support <EM>extended</EM> <EM>color</EM> <EM>pairs</EM>:
- <STRONG>o</STRONG> For functions which modify the color, e.g., <STRONG>wattr_set</STRONG>, if <EM>opts</EM> is
- set it is treated as a pointer to <STRONG>int</STRONG>, and used to set the color
- pair instead of the <STRONG>short</STRONG> <EM>pair</EM> parameter.
+ <STRONG>o</STRONG> For functions which modify the color, e.g., <STRONG>wattr_set</STRONG> and <STRONG>wattr_on</STRONG>,
+ if <EM>opts</EM> is set it is treated as a pointer to <STRONG>int</STRONG>, and used to set
+ the color pair instead of the <STRONG>short</STRONG> <EM>pair</EM> parameter.
<STRONG>o</STRONG> For functions which retrieve the color, e.g., <STRONG>wattr_get</STRONG>, if <EM>opts</EM> is
set it is treated as a pointer to <STRONG>int</STRONG>, and used to retrieve the
- color pair as an <STRONG>int</STRONG> value, in addition retrieving it via the stan-
- dard pointer to <STRONG>short</STRONG> parameter.
+ color pair as an <STRONG>int</STRONG> value, in addition to retrieving it via the
+ standard pointer to <STRONG>short</STRONG> parameter.
- The remaining functions which have <EM>opts</EM>, but do not manipulate color,
- e.g., <STRONG>wattr_on</STRONG> and <STRONG>wattr_off</STRONG> are not used by this implementation except
- to check that they are <STRONG>NULL</STRONG>.
+ <STRONG>o</STRONG> For functions which turn attributes off, e.g., <STRONG>wattr_off</STRONG>, the <EM>opts</EM>
+ parameter is ignored except except to check that it is <STRONG>NULL</STRONG>.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
These functions are supported in the XSI Curses standard, Issue 4. The
- standard defined the dedicated type for highlights, <STRONG>attr_t</STRONG>, which was
+ standard defined the dedicated type for highlights, <STRONG>attr_t</STRONG>, which was
not defined in SVr4 curses. The functions taking <STRONG>attr_t</STRONG> arguments were
not supported under SVr4.
Very old versions of this library did not force an update of the screen
- when changing the attributes. Use <STRONG>touchwin</STRONG> to force the screen to
+ when changing the attributes. Use <STRONG>touchwin</STRONG> to force the screen to
match the updated attributes.
- The XSI Curses standard states that whether the traditional functions
- <STRONG>attron</STRONG>/<STRONG>attroff</STRONG>/<STRONG>attrset</STRONG> can manipulate attributes other than <STRONG>A_BLINK</STRONG>,
- <STRONG>A_BOLD</STRONG>, <STRONG>A_DIM</STRONG>, <STRONG>A_REVERSE</STRONG>, <STRONG>A_STANDOUT</STRONG>, or <STRONG>A_UNDERLINE</STRONG> is "unspecified".
- Under this implementation as well as SVr4 curses, these functions cor-
- rectly manipulate all other highlights (specifically, <STRONG>A_ALTCHARSET</STRONG>,
+ The XSI Curses standard states that whether the traditional functions
+ <STRONG>attron</STRONG>/<STRONG>attroff</STRONG>/<STRONG>attrset</STRONG> can manipulate attributes other than <STRONG>A_BLINK</STRONG>,
+ <STRONG>A_BOLD</STRONG>, <STRONG>A_DIM</STRONG>, <STRONG>A_REVERSE</STRONG>, <STRONG>A_STANDOUT</STRONG>, or <STRONG>A_UNDERLINE</STRONG> is "unspecified".
+ Under this implementation as well as SVr4 curses, these functions
+ correctly manipulate all other highlights (specifically, <STRONG>A_ALTCHARSET</STRONG>,
<STRONG>A_PROTECT</STRONG>, and <STRONG>A_INVIS</STRONG>).
XSI Curses added these entry points:
- <STRONG>attr_get</STRONG>, <STRONG>attr_on</STRONG>, <STRONG>attr_off</STRONG>, <STRONG>attr_set</STRONG>, <STRONG>wattr_on</STRONG>, <STRONG>wattr_off</STRONG>, <STRONG>wat-</STRONG>
- <STRONG>tr_get</STRONG>, <STRONG>wattr_set</STRONG>
+ <STRONG>attr_get</STRONG>, <STRONG>attr_on</STRONG>, <STRONG>attr_off</STRONG>, <STRONG>attr_set</STRONG>, <STRONG>wattr_on</STRONG>, <STRONG>wattr_off</STRONG>,
+ <STRONG>wattr_get</STRONG>, <STRONG>wattr_set</STRONG>
- The new functions are intended to work with a new series of highlight
+ The new functions are intended to work with a new series of highlight
macros prefixed with <STRONG>WA_</STRONG>. The older macros have direct counterparts in
the newer set of names:
- <EM>Name</EM> <EM>Description</EM>
+ <STRONG>Name</STRONG> <STRONG>Description</STRONG>
------------------------------------------------------------
<STRONG>WA_NORMAL</STRONG> Normal display (no highlight)
<STRONG>WA_STANDOUT</STRONG> Best highlighting mode of the terminal.
<STRONG>WA_BOLD</STRONG> Extra bright or bold
<STRONG>WA_ALTCHARSET</STRONG> Alternate character set
- XSI curses does not assign values to these symbols, nor does it state
+ XSI curses does not assign values to these symbols, nor does it state
whether or not they are related to the similarly-named A_NORMAL, etc.:
- <STRONG>o</STRONG> The XSI curses standard specifies that each pair of corresponding
- <STRONG>A_</STRONG> and <STRONG>WA_</STRONG>-using functions operates on the same current-highlight
+ <STRONG>o</STRONG> The XSI curses standard specifies that each pair of corresponding
+ <STRONG>A_</STRONG> and <STRONG>WA_</STRONG>-using functions operates on the same current-highlight
information.
- <STRONG>o</STRONG> However, in some implementations, those symbols have unrelated val-
- ues.
+ <STRONG>o</STRONG> However, in some implementations, those symbols have unrelated
+ values.
For example, the Solaris <EM>xpg4</EM> (X/Open) curses declares <STRONG>attr_t</STRONG> to be
- an unsigned short integer (16-bits), while <STRONG>chtype</STRONG> is a unsigned in-
- teger (32-bits). The <STRONG>WA_</STRONG> symbols in this case are different from
- the <STRONG>A_</STRONG> symbols because they are used for a smaller datatype which
+ an unsigned short integer (16-bits), while <STRONG>chtype</STRONG> is a unsigned
+ integer (32-bits). The <STRONG>WA_</STRONG> symbols in this case are different from
+ the <STRONG>A_</STRONG> symbols because they are used for a smaller datatype which
does not represent <STRONG>A_CHARTEXT</STRONG> or <STRONG>A_COLOR</STRONG>.
In this implementation (as in many others), the values happen to be
- the same because it simplifies copying information between <STRONG>chtype</STRONG>
+ the same because it simplifies copying information between <STRONG>chtype</STRONG>
and <STRONG>cchar_t</STRONG> variables.
- The XSI standard extended conformance level adds new highlights <STRONG>A_HORI-</STRONG>
- <STRONG>ZONTAL</STRONG>, <STRONG>A_LEFT</STRONG>, <STRONG>A_LOW</STRONG>, <STRONG>A_RIGHT</STRONG>, <STRONG>A_TOP</STRONG>, <STRONG>A_VERTICAL</STRONG> (and corresponding
- <STRONG>WA_</STRONG> macros for each). As of August 2013, no known terminal provides
- these highlights (i.e., via the <STRONG>sgr1</STRONG> capability).
+ <STRONG>o</STRONG> Because ncurses's <STRONG>attr_t</STRONG> can hold a color pair (in the <STRONG>A_COLOR</STRONG>
+ field), a call to <STRONG>wattr_on</STRONG>, <STRONG>wattr_off</STRONG>, or <STRONG>wattr_set</STRONG> may alter the
+ window's color. If the color pair information in the attribute
+ parameter is zero, no change is made to the window's color.
+
+ This is consistent with SVr4 curses; X/Open Curses does not specify
+ this.
+
+ The XSI standard extended conformance level adds new highlights
+ <STRONG>A_HORIZONTAL</STRONG>, <STRONG>A_LEFT</STRONG>, <STRONG>A_LOW</STRONG>, <STRONG>A_RIGHT</STRONG>, <STRONG>A_TOP</STRONG>, <STRONG>A_VERTICAL</STRONG> (and
+ corresponding <STRONG>WA_</STRONG> macros for each). As of August 2013, no known
+ terminal provides these highlights (i.e., via the <STRONG>sgr1</STRONG> capability).
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
<STRONG>o</STRONG> returns an error if the window pointer is null.
- <STRONG>o</STRONG> returns an error if the color pair parameter for <STRONG>wcolor_set</STRONG> is out-
- side the range 0..COLOR_PAIRS-1.
+ <STRONG>o</STRONG> returns an error if the color pair parameter for <STRONG>wcolor_set</STRONG> is
+ outside the range 0..COLOR_PAIRS-1.
- <STRONG>o</STRONG> does not return an error if either of the parameters of <STRONG>wattr_get</STRONG>
+ <STRONG>o</STRONG> does not return an error if either of the parameters of <STRONG>wattr_get</STRONG>
used for retrieving attribute or color-pair values is <STRONG>NULL</STRONG>.
- Functions with a "mv" prefix first perform a cursor movement using
+ 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
the window pointer is null.
</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_addstr.3x.html">curs_addstr(3x)</A></STRONG>, <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></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_addstr.3x.html">curs_addstr(3x)</A></STRONG>, <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>,
<STRONG><A HREF="curs_printw.3x.html">curs_printw(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>
-
<STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
+
ncurses 6.4 2023-10-07 <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>
</PRE>
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