NAME
curses_color,
has_colors,
can_change_color,
start_color, init_pair,
pair_content, COLOR_PAIR,
PAIR_NUMBER, init_color,
color_content,
no_color_attributes —
curses color manipulation
routines
LIBRARY
library “libcurses”
SYNOPSIS
#include
<curses.h>
bool
has_colors(void);
bool
can_change_color(void);
int
start_color(void);
int
init_pair(short
pair, short fore,
short back);
int
pair_content(short
pair, short *fore,
short *back);
int
COLOR_PAIR(int
n);
int
PAIR_NUMBER(int
val);
int
init_color(short
color, short red,
short green,
short blue);
int
color_content(short
color, short *red,
short *green,
short *blue);
attr_t
no_color_attributes(void);
extern int COLOR_PAIRS;
extern int COLORS;
DESCRIPTION
These functions manipulate color on terminals that support color attributes.The function
has_colors()
indicates whether a terminal is capable of displaying color attributes. It
returns TRUE if the terminal is capable of
displaying color attributes and FALSE otherwise.
The function
can_change_color()
indicates whether a terminal is capable of redefining colors. It returns
TRUE if colors can be redefined and
FALSE if they can not.
The function
start_color()
initializes the curses color support on a terminal. It must be called before
any color manipulation functions are called on that terminal. The function
initializes the eight basic colors (black, red, green, yellow, blue,
magenta, cyan and white) that are specified using the color macros (such as
COLOR_BLACK) defined in
<curses.h>.
start_color() also initializes the global external
variables COLORS and
COLOR_PAIRS. COLORS defines the
number of colors that the terminal supports and
COLOR_PAIRS defines the number of color-pairs that the
terminal supports. These color-pairs are initialized to white foreground on
black background. start_color() sets the colors on
the terminal to the curses defaults of white foreground on black background
unless the functions assume_default_colors() or
use_default_colors()
have been called previously.
The function
init_pair(pair,
fore, back) sets foreground
color fore and background color
back for color-pair number pair.
The valid range for the color-pair pair is from 1 to
COLOR_PAIRS - 1 and the valid range for the colors is
any number less than COLORS. Specifying a negative
number will set that color to the default foreground or background color.
The 8 initial colors are defined as:
- COLOR_BLACK
- COLOR_RED
- COLOR_GREEN
- COLOR_YELLOW
- COLOR_BLUE
- COLOR_MAGENTA
- COLOR_CYAN
- COLOR_WHITE
assume_default_colors()
to change the default colors.
The function
pair_content(pair,
*fore, *back) stores the
foreground and background color numbers of color-pair
pair in the variables fore and
back, respectively.
The macro
COLOR_PAIR(n)
gives the attribute value of color-pair number n. This
is the value that is used to set the attribute of a character to this
color-pair. For example,
attrset(COLOR_PAIR(2))The macro
PAIR_NUMBER(val)
gives the color-pair number associated with the attribute value
val.
The function
init_color(color,
red, green,
blue) sets the red, green and blue intensity
components of color color to the values
red, green and
blue, respectively. The minimum intensity value is 0
and the maximum intensity value is 1000.
The function
color_content(color,
*red, *green,
*blue) stores the red, green and blue intensity
components of color color in the variables
red, green, and
blue, respectively.
The function
no_color_attributes()
returns those attributes that a terminal is unable to combine with
color.
RETURN VALUES
The functions start_color(),
init_pair(), pair_content(),
init_color() and
color_content() return OK on success and ERR on
failure.
SEE ALSO
curses_attributes(3), curses_background(3), curses_default_colors(3)
STANDARDS
The NetBSD Curses library complies with the X/Open Curses specification, part of the Single Unix Specification.
The function no_color_attributes() and the
use of negative color numbers are extensions to the X/Open Curses
specification.
HISTORY
These functions first appeared in NetBSD 1.5.