+ use_default_colors, assume_default_colors - use terminal's default
+ colors in curses
-
-
DESCRIPTION
- The use_default_colors() and assume_default_colors() func-
- tions are extensions to the curses library. They are used
- with terminals that support ISO 6429 color, or equivalent.
- These terminals allow the application to reset color to an
- unspecified default value (e.g., with SGR 39 or SGR 49).
-
- Applications that paint a colored background over the
- whole screen do not take advantage of SGR 39 and SGR 49.
- Some applications are designed to work with the default
- background, using colors only for text. For example,
- there are several implementations of the ls program which
- use colors to denote different file types or permissions.
- These "color ls" programs do not necessarily modify the
- background color, typically using only the setaf terminfo
- capability to set the foreground color. Full-screen
- applications that use default colors can achieve similar
- visual effects.
-
- The first function, use_default_colors() tells the curses
- library to assign terminal default foreground/background
- colors to color number -1. So init_pair(x,COLOR_RED,-1)
- will initialize pair x as red on default background and
- init_pair(x,-1,COLOR_BLUE) will initialize pair x as
- default foreground on blue.
-
- The other, assume_default_colors() is a refinement which
- tells which colors to paint for color pair 0. This func-
- tion recognizes a special color number -1, which denotes
- the default terminal color.
+
+ The use_default_colors and assume_default_colors functions are
+ extensions to the curses library. They are used with terminals that
+ support ISO 6429 color, or equivalent. These terminals allow the
+ application to reset color to an unspecified default value (e.g., with
+ SGR 39 or SGR 49).
+
+ Applications that paint a colored background over the whole screen do
+ not take advantage of SGR 39 and SGR 49. Some applications are
+ designed to work with the default background, using colors only for
+ text. For example, there are several implementations of the ls program
+ which use colors to denote different file types or permissions. These
+ "color ls" programs do not necessarily modify the background color,
+ typically using only the setaf terminfo capability to set the
+ foreground color. Full-screen applications that use default colors can
+ achieve similar visual effects.
+
+ The first function, use_default_colors tells the curses library to
+ assign terminal default foreground/background colors to color number
+ -1. So init_pair(x,COLOR_RED,-1) will initialize pair x as red on
+ default background and init_pair(x,-1,COLOR_BLUE) will initialize pair
+ x as default foreground on blue.
+
+ The other, assume_default_colors is a refinement which tells which
+ colors to paint for color pair 0. This function recognizes a special
+ color number -1, which denotes the default terminal color.
The following are equivalent:
use_default_colors();assume_default_colors(-1,-1);
- These are ncurses extensions. For other curses implemen-
- tations, color number -1 does not mean anything, just as
- for ncurses before a successful call of use_default_col-
- ors() or assume_default_colors().
-
- Other curses implementations do not allow an application
- to modify color pair 0. They assume that the background
- is COLOR_BLACK, but do not ensure that the color pair 0 is
- painted to match the assumption. If your application does
- not use either use_default_colors() or assume_default_col-
- ors() ncurses will paint a white foreground (text) with
- black background for color pair 0.
-
-
-
-
RETURN VALUE
- These functions return the integer ERR upon failure and OK
- on success. They will fail if either the terminal does
- not support the orig_pair or orig_colors capability. If
- the initialize_pair capability is found, this causes an
- error as well.
-
-
-
-
NOTES
- Associated with this extension, the init_pair(3x) function
- accepts negative arguments to specify default foreground
- or background colors.
-
-
-
-
PORTABILITY
- These routines are specific to ncurses. They were not
- supported on Version 7, BSD or System V implementations.
- It is recommended that any code depending on them be con-
- ditioned using NCURSES_VERSION.
-
-
-
- Thomas Dickey (from an analysis of the requirements for
- color xterm for XFree86 3.1.2C, February 1996).
-
-
-
-
-
-
-
-
-
-
+ These are ncurses extensions. For other curses implementations, color
+ number -1 does not mean anything, just as for ncurses before a
+ successful call of use_default_colors or assume_default_colors.
+ Other curses implementations do not allow an application to modify
+ color pair 0. They assume that the background is COLOR_BLACK, but do
+ not ensure that the color pair 0 is painted to match the assumption.
+ If your application does not use either use_default_colors or
+ assume_default_colorsncurses will paint a white foreground (text) with
+ black background for color pair 0.
+
+ These functions return the integer ERR upon failure and OK on success.
+ They will fail if either the terminal does not support the orig_pair or
+ orig_colors capability. If the initialize_pair capability is not
+ found, this causes an error as well.
+
+ Associated with this extension, the init_pair function accepts negative
+ arguments to specify default foreground or background colors.
+ The use_default_colors function was added to support ded. This is a
+ full-screen application which uses curses to manage only part of the
+ screen. The bottom portion of the screen, which is of adjustable size,
+ is left uncolored to display the results from shell commands. The top
+ portion of the screen colors filenames using a scheme like the "color
+ ls" programs. Attempting to manage the background color of the screen
+ for this application would give unsatisfactory results for a variety of
+ reasons. This extension was devised after noting that color xterm (and
+ similar programs) provides a background color which does not
+ necessarily correspond to any of the ANSI colors. While a special
+ terminfo entry could be constructed using nine colors, there was no
+ mechanism provided within curses to account for the related orig_pair
+ and back_color_erase capabilities.
+ The assume_default_colors function was added to solve a different
+ problem: support for applications which would use environment variables
+ and other configuration to bypass curses' notion of the terminal's
+ default colors, setting specific values.
+
+ These routines are specific to ncurses. They were not supported on
+ Version 7, BSD or System V implementations. It is recommended that any
+ code depending on them be conditioned using NCURSES_VERSION.
+