These routines manipulate the current attributes of the
- named window. The current attributes of a window apply to
- all characters that are written into the window with wadd-
- ch, waddstr and wprintw. Attributes are a property of the
- 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.
-
- The routine attrset sets the current attributes of the
- given window to attrs. The routine attroff turns off the
- named attributes without turning any other attributes on
- or off. The routine attron turns on the named attributes
- without affecting any others. The routine standout is the
- same as attron(A_STANDOUT). The routine standend is the
- same as attrset(A_NORMAL) or attrset(0), that is, it turns
- off all attributes.
-
- The attrset and related routines do not affect the at-
- tributes used when erasing portions of the window. See
- curs_bkgd(3x) for functions which modify the attributes
- used for erasing and clearing.
-
- The routine color_set sets the current color of the given
- window to the foreground/background combination described
- by the color_pair_number. The parameter opts is reserved
- for future use, applications must supply a null pointer.
-
- The routine wattr_get returns the current attribute and
- color pair for the given window; attr_get returns the cur-
- rent attribute and color pair for stdscr. The remaining
- attr_* functions operate exactly like the corresponding
- attr* functions, except that they take arguments of type
- attr_t rather than int.
+ named window, which then apply to all characters that are
+ written into the window with waddch, waddstr and wprintw.
+ Attributes are a property of the 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 curs_bkgd(3x) for
+ functions which modify the attributes used for erasing and
+ clearing.
+
+ Routines which do not have a WINDOW* parameter apply to
+ stdscr. For example, attr_set is the stdscr variant of
+ wattr_set.
+
+
+
+ There are two sets of functions:
+
+ o functions for manipulating the window attributes and
+ color: wattr_set and wattr_get.
+
+ o functions for manipulating only the window attributes
+ (not color): wattr_on and wattr_off.
+
+ The wattr_set function sets the current attributes of the
+ given window to attrs, with color specified by pair.
+ Use wattr_get to retrieve attributes for the given window.
+
+ Use attr_on and wattr_on to turn on window attributes,
+ i.e., values OR'd together in attr, without affecting oth-
+ er attributes. Use attr_off and wattr_off to turn off
+ window attributes, again values OR'd together in attr,
+ without affecting other attributes.
+
+
+
+ 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 (_).
+
+ The attrset routine is a legacy feature predating SVr4
+ curses but kept in X/Open Curses for the same reason that
+ SVr4 curses kept it: compatibility.
+
+ The remaining attr* functions operate exactly like the
+ corresponding attr_* functions, except that they take ar-
+ guments of type int rather than attr_t.
+
+ There is no corresponding attrget function as such in
+ X/Open Curses, although ncurses provides getattrs (see
+ curs_legacy(3x)).
+
+
+
The routine chgat changes the attributes of a given number
of characters starting at the current cursor location of
stdscr. It does not update the cursor and does not per-
@@ -137,35 +175,65 @@
the remaining window width means to change attributes all
the way to the end of the current line. The wchgat func-
tion generalizes this to any window; the mvwchgat function
- does a cursor move before acting. In these functions, the
- color argument is a color-pair index (as in the first ar-
- gument of init_pair, see curs_color(3x)). The opts argu-
- ment is not presently used, but is reserved for the future
- (leave it NULL).
+ does a cursor move before acting.
+
+ In these functions, the color pair argument is a color-
+ pair index (as in the first argument of init_pair, see
+ curs_color(3x)).
- Attributes
- The following video attributes, defined in <curses.h>, can
- be passed to the routines attron, attroff, and attrset, or
- OR'd with the characters passed to addch.
+
+ The routine color_set sets the current color of the given
+ window to the foreground/background combination described
+ by the color pair parameter.
- A_NORMAL Normal display (no highlight)
- A_STANDOUT Best highlighting mode of the terminal.
- A_UNDERLINE Underlining
- A_REVERSE Reverse video
- A_BLINK Blinking
- A_DIM Half bright
- A_BOLD Extra bright or bold
- A_PROTECT Protected mode
- A_INVIS Invisible or blank mode
- A_ALTCHARSET Alternate character set
- A_CHARTEXT Bit-mask to extract a character
- COLOR_PAIR(n) Color-pair number n
- The following macro is the reverse of COLOR_PAIR(n):
+
+ The routine standout is the same as attron(A_STANDOUT).
+ The routine standend is the same as attrset(A_NORMAL) or
+ attrset(0), that is, it turns off all attributes.
- PAIR_NUMBER(attrs) Returns the pair number associated
- with the COLOR_PAIR(n) attribute.
+ X/Open does not mark these "restricted", because
+
+ o they have well established legacy use, and
+
+ o there is no ambiguity about the way the attributes
+ might be combined with a color pair.
+
+
+
+ The following video attributes, defined in <curses.h>, can
+ be passed to the routines attron, attroff, and attrset, or
+ OR'd with the characters passed to addch (see curs_add-
+ ch(3x)).
+
+ NameDescription
+ -----------------------------------------------------------
+ A_NORMAL Normal display (no highlight)
+ A_STANDOUT Best highlighting mode of the terminal.
+ A_UNDERLINE Underlining
+ A_REVERSE Reverse video
+ A_BLINK Blinking
+ A_DIM Half bright
+ A_BOLD Extra bright or bold
+ A_PROTECT Protected mode
+ A_INVIS Invisible or blank mode
+ A_ALTCHARSET Alternate character set
+ A_ITALIC Italics (non-X/Open extension)
+ A_CHARTEXT Bit-mask to extract a character
+
+ These video attributes are supported by attr_on and relat-
+ ed functions (which also support the attributes recognized
+ by attron, etc.):
+
+ NameDescription
+ -----------------------------------------
+ WA_HORIZONTAL Horizontal highlight
+ WA_LEFT Left highlight
+ WA_LOW Low highlight
+ WA_RIGHT Right highlight
+ WA_TOP Top highlight
+ WA_VERTICAL Vertical highlight
The return values of many of these routines are not mean-
ingful (they are implemented as macro-expanded assignments
@@ -173,12 +241,13 @@
claims (falsely) that these routines always return 1.
-
-
NOTES
- Note that attroff, wattroff, attron, wattron, attrset,
- wattrset, standend and standout may be macros.
+
+ These functions may be macros:
+
+ attroff, wattroff, attron, wattron, attrset, wat-
+ trset, standend and standout.
- COLOR_PAIR values can only be OR'd with attributes if the
+ Color pair values can only be OR'd with attributes if the
pair number is less than 256. The alternate functions
such as color_set can pass a color pair value directly.
However, ncurses ABI 4 and 5 simply OR this value within
@@ -186,14 +255,49 @@
support more than 256 color pairs.
-
+ This implementation provides the A_ITALIC attribute for
+ terminals which have the enter_italics_mode (sitm) and ex-
+ it_italics_mode (ritm) capabilities. Italics are not men-
+ tioned in X/Open Curses. Unlike the other video at-
+ tributes, A_ITALIC is unrelated to the set_attributes ca-
+ pabilities. This implementation makes the assumption that
+ exit_attribute_mode may also reset italics.
+
+ Each of the functions added by XSI Curses has a parameter
+ opts, which X/Open Curses still (after more than twenty
+ years) documents as reserved for future use, saying that
+ it should be NULL. This implementation uses that parame-
+ ter in ABI 6 for the functions which have a color-pair pa-
+ rameter to support extendedcolorpairs:
+
+ o For functions which modify the color, e.g., wattr_set,
+ if opts is set it is treated as a pointer to int, and
+ used to set the color pair instead of the shortpair
+ parameter.
+
+ o For functions which retrieve the color, e.g., wat-
+ tr_get, if opts is set it is treated as a pointer to
+ int, and used to retrieve the color pair as an int
+ value, in addition retrieving it via the standard
+ pointer to short parameter.
+
+ The remaining functions which have opts, but do not manip-
+ ulate color, e.g., wattr_on and wattr_off are not used by
+ this implementation except to check that they are NULL.
+
+
+
These functions are supported in the XSI Curses standard,
Issue 4. The standard defined the dedicated type for
- highlights, attr_t, which is not defined in SVr4 curses.
- The functions taking attr_t arguments are not supported
+ highlights, attr_t, which was not defined in SVr4 curses.
+ The functions taking attr_t 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 touchwin
+ to force the screen to match the updated attributes.
+
The XSI Curses standard states that whether the tradition-
al functions attron/attroff/attrset can manipulate at-
tributes other than A_BLINK, A_BOLD, A_DIM, A_REVERSE,
@@ -202,24 +306,25 @@
correctly manipulate all other highlights (specifically,
A_ALTCHARSET, A_PROTECT, and A_INVIS).
- XSI Curses added the new entry points, attr_get, attr_on,
- attr_off, attr_set, wattr_on, wattr_off, wattr_get, wat-
- tr_set. These are intended to work with a new series of
- highlight macros prefixed with WA_.
+ XSI Curses added these entry points:
- Older versions of this library did not force an update of
- the screen when changing the attributes. Use touchwin to
- force the screen to match the updated attributes.
+ attr_get, attr_on, attr_off, attr_set, wattr_on,
+ wattr_off, wattr_get, wattr_set
+ The new functions are intended to work with a new series
+ of highlight macros prefixed with WA_. The older macros
+ have direct counterparts in the newer set of names:
- WA_NORMAL Normal display (no highlight)
- WA_STANDOUT Best highlighting mode of the terminal.
- WA_UNDERLINE Underlining
- WA_REVERSE Reverse video
- WA_BLINK Blinking
- WA_DIM Half bright
- WA_BOLD Extra bright or bold
- WA_ALTCHARSET Alternate character set
+ NameDescription
+ ------------------------------------------------------------
+ WA_NORMAL Normal display (no highlight)
+ WA_STANDOUT Best highlighting mode of the terminal.
+ WA_UNDERLINE Underlining
+ WA_REVERSE Reverse video
+ WA_BLINK Blinking
+ WA_DIM Half bright
+ WA_BOLD Extra bright or bold
+ WA_ALTCHARSET Alternate character set
The XSI curses standard specifies that each pair of corre-
sponding A_ and WA_-using functions operates on the same
@@ -227,36 +332,61 @@
The XSI standard extended conformance level adds new high-
lights A_HORIZONTAL, A_LEFT, A_LOW, A_RIGHT, A_TOP, A_VER-
- TICAL (and corresponding WA_ macros for each) which this
- implementation does not yet support.
+ TICAL (and corresponding WA_ macros for each). As of Au-
+ gust 2013, no known terminal provides these highlights
+ (i.e., via the sgr1 capability).
-
-
RETURN VALUE
- All routines return the integer OK on success, or ERR on
+
+ All routines return the integer OK on success, or ERR on
failure.
X/Open does not define any error conditions.
- This implementation returns an error if the window pointer
- is null. The wcolor_set function returns an error if the
- color pair parameter is outside the range 0..COL-
- OR_PAIRS-1.
+ This implementation
+ o returns an error if the window pointer is null.
-
-
SEE ALSO
- curses(3x), curs_addch(3x), curs_addstr(3x),
- curs_bkgd(3x), curs_printw(3x)
+ o returns an error if the color pair parameter for wcol-
+ or_set is outside the range 0..COLOR_PAIRS-1.
+
+ o does not return an error if either of the parameters
+ of wattr_get used for retrieving attribute or color-
+ pair values is NULL.
+
+ Functions with a "mv" prefix first perform a cursor move-
+ ment using wmove, and return an error if the position is
+ outside the window, or if the window pointer is null.
+
+
+