X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_color.3x.html;h=cf446d172566445aa7beaf97177a39f72f78abee;hp=5ff2f5f949488853b87ecf1b33158e8f1a69c265;hb=f344f8539c1543f8cd65a5bb142dbaf23b9421d2;hpb=027d0c57c4c4d6690e8d8727888d3282dbe9aa86;ds=inline
diff --git a/doc/html/man/curs_color.3x.html b/doc/html/man/curs_color.3x.html
index 5ff2f5f9..cf446d17 100644
--- a/doc/html/man/curs_color.3x.html
+++ b/doc/html/man/curs_color.3x.html
@@ -1,6 +1,6 @@
@@ -45,42 +48,43 @@
-
-
+
start_color, init_pair, init_color, has_colors,
- can_change_color, color_content, pair_content, COLOR_PAIR
- - curses color manipulation routines
+ can_change_color, color_content, pair_content, COLOR_PAIR,
+ PAIR_NUMBER - curses color manipulation routines
-
-
- # include <curses.h>
+
+ #include <curses.h>
int start_color(void);
int init_pair(short pair, short f, short b);
int init_color(short color, short r, short g, short b);
+
bool has_colors(void);
bool can_change_color(void);
+
int color_content(short color, short *r, short *g, short
*b);
int pair_content(short pair, short *f, short *b);
+ int COLOR_PAIR(int n);
+ PAIR_NUMBER(attrs);
-
-
-
-
- curses support color attributes on terminals with that ca-
- pability. To use these routines start_color must be
+
+
+
+ curses supports color attributes on terminals with that
+ capability. To use these routines start_color must be
called, usually right after initscr. Colors are always
used in pairs (referred to as color-pairs). A color-pair
consists of a foreground color (for characters) and a
background color (for the blank field on which the charac-
ters are displayed). A programmer initializes a color-
pair with the routine init_pair. After it has been ini-
- tialized, COLOR_PAIR(n), a macro defined in <curses.h>,
- can be used as a new video attribute.
+ tialized, COLOR_PAIR(n) can be used to convert the pair to
+ a video attribute.
If a terminal is capable of redefining colors, the pro-
grammer can use the routine init_color to change the defi-
@@ -94,26 +98,70 @@
how a given color-pair is currently defined.
-
-
+
+ The curses library combines these inputs to produce the
+ actual foreground and background colors shown on the
+ screen:
+
+ o per-character video attributes (e.g., via waddch),
+
+ o the window attribute (e.g., by wattrset), and
+
+ o the background character (e.g., wbkgdset).
+
+ Per-character and window attributes are usually set by a
+ parameter containing video attributes including a color
+ pair value. Some functions such as wattr_set use a sepa-
+ rate parameter which is the color pair number.
+
+ The background character is a special case: it includes a
+ character value, just as if it were passed to waddch.
+
+ The curses library does the actual work of combining these
+ color pairs in an internal function called from waddch:
+
+ o If the parameter passed to waddch is blank, and it us-
+ es the special color pair 0,
+
+ o curses next checks the window attribute.
+
+ o If the window attribute does not use color pair 0,
+ curses uses the color pair from the window at-
+ tribute.
+
+ o Otherwise, curses uses the background character.
+
+ o If the parameter passed to waddch is not blank, or it
+ does not use the special color pair 0, curses prefers
+ the color pair from the parameter, if it is nonzero.
+ Otherwise, it tries the window attribute next, and fi-
+ nally the background character.
+
+ Some curses functions such as wprintw call waddch. Those
+ do not combine its parameter with a color pair. Conse-
+ quently those calls use only the window attribute or the
+ background character.
+
+
+
The start_color routine requires no arguments. It must be
- called if the programmer wants to use colors, and before
- any other color manipulation routine is called. It is
- good practice to call this routine right after initscr.
+ called if the programmer wants to use colors, and before
+ any other color manipulation routine is called. It is
+ good practice to call this routine right after initscr.
start_color does this:
- o It initializes two global variables, COLORS and COL-
- OR_PAIRS (respectively defining the maximum number of
+ o It initializes two global variables, COLORS and COL-
+ OR_PAIRS (respectively defining the maximum number of
colors and color-pairs the terminal can support).
o It initializes the special color pair 0 to the default
- foreground and background colors. No other color
+ foreground and background colors. No other color
pairs are initialized.
- o It restores the colors on the terminal to the values
+ o It restores the colors on the terminal to the values
they had when the terminal was just turned on.
- o If the terminal supports the initc (initialize_color)
+ o If the terminal supports the initc (initialize_color)
capability, start_color initializes its internal table
representing the red, green and blue components of the
color palette.
@@ -121,18 +169,18 @@
The components depend on whether the terminal uses CGA
(aka "ANSI") or HLS (i.e., the hls (hue_lightness_sat-
uration) capability is set). The table is initialized
- first for eight basic colors (black, red, green, yel-
- low, blue, magenta, cyan, and white), and after that
- (if the terminal supports more than eight colors) the
+ first for eight basic colors (black, red, green, yel-
+ low, blue, magenta, cyan, and white), and after that
+ (if the terminal supports more than eight colors) the
components are initialized to 1000.
- start_color does not attempt to set the terminal's
- color palette to match its built-in table. An appli-
- cation may use init_color to alter the internal table
+ start_color does not attempt to set the terminal's
+ color palette to match its built-in table. An appli-
+ cation may use init_color to alter the internal table
along with the terminal's color.
- These limits apply to color values and color pairs. Val-
- ues outside these limits are not legal, and may result in
+ These limits apply to color values and color pairs. Val-
+ ues outside these limits are not legal, and may result in
a runtime error:
o COLORS corresponds to the terminal database's max_col-
@@ -142,97 +190,106 @@
o color values are expected to be in the range 0 to COL-
ORS-1, inclusive (including 0 and COLORS-1).
- o a special color value -1 is used in certain extended
- functions to denote the default color (see use_de-
+ o a special color value -1 is used in certain extended
+ functions to denote the default color (see use_de-
fault_colors).
- o COLOR_PAIRS corresponds to the terminal database's
- max_pairs capability, which is typically a signed
+ o COLOR_PAIRS corresponds to the terminal database's
+ max_pairs capability, which is typically a signed
16-bit integer (see terminfo(5)).
- o legal color pair values are in the range 1 to COL-
+ o legal color pair values are in the range 1 to COL-
OR_PAIRS-1, inclusive.
o color pair 0 is special; it denotes "no color".
- Color pair 0 is assumed to be white on black, but is
+ Color pair 0 is assumed to be white on black, but is
actually whatever the terminal implements before color
is initialized. It cannot be modified by the applica-
tion.
- The init_pair routine changes the definition of a color-
- pair. It takes three arguments: the number of the color-
- pair to be changed, the foreground color number, and the
+ The init_pair routine changes the definition of a color-
+ pair. It takes three arguments: the number of the color-
+ pair to be changed, the foreground color number, and the
background color number. For portable applications:
- o The first argument must be a legal color pair value.
- If default colors are used (see use_default_colors)
- the upper limit is adjusted to allow for extra pairs
- which use a default color in foreground and/or back-
+ o The first argument must be a legal color pair value.
+ If default colors are used (see use_default_colors)
+ the upper limit is adjusted to allow for extra pairs
+ which use a default color in foreground and/or back-
ground.
- o The second and third arguments must be legal color
+ o The second and third arguments must be legal color
values.
- If the color-pair was previously initialized, the screen
- is refreshed and all occurrences of that color-pair are
+ If the color-pair was previously initialized, the screen
+ is refreshed and all occurrences of that color-pair are
changed to the new definition.
- As an extension, ncurses allows you to set color pair 0
- via the assume_default_colors routine, or to specify the
- use of default colors (color number -1) if you first in-
+ As an extension, ncurses allows you to set color pair 0
+ via the assume_default_colors routine, or to specify the
+ use of default colors (color number -1) if you first in-
voke the use_default_colors routine.
- The init_color routine changes the definition of a color.
- It takes four arguments: the number of the color to be
- changed followed by three RGB values (for the amounts of
+ The init_color routine changes the definition of a color.
+ It takes four arguments: the number of the color to be
+ changed followed by three RGB values (for the amounts of
red, green, and blue components). The first argument must
- be a legal color value; default colors are not allowed
- here. (See the section Colors for the default color in-
+ be a legal color value; default colors are not allowed
+ here. (See the section Colors for the default color in-
dex.) Each of the last three arguments must be a value in
- the range 0 through 1000. When init_color is used, all
+ the range 0 through 1000. When init_color is used, all
occurrences of that color on the screen immediately change
to the new definition.
- The has_colors routine requires no arguments. It returns
- TRUE if the terminal can manipulate colors; otherwise, it
+ The has_colors routine requires no arguments. It returns
+ TRUE if the terminal can manipulate colors; otherwise, it
returns FALSE. This routine facilitates writing terminal-
- independent programs. For example, a programmer can use
- it to decide whether to use color or some other video at-
+ independent programs. For example, a programmer can use
+ it to decide whether to use color or some other video at-
tribute.
- The can_change_color routine requires no arguments. It
- returns TRUE if the terminal supports colors and can
- change their definitions; other, it returns FALSE. This
+ The can_change_color routine requires no arguments. It
+ returns TRUE if the terminal supports colors and can
+ change their definitions; other, it returns FALSE. This
routine facilitates writing terminal-independent programs.
- The color_content routine gives programmers a way to find
+ The color_content routine gives programmers a way to find
the intensity of the red, green, and blue (RGB) components
in a color. It requires four arguments: the color number,
- and three addresses of shorts for storing the information
- about the amounts of red, green, and blue components in
+ and three addresses of shorts for storing the information
+ about the amounts of red, green, and blue components in
the given color. The first argument must be a legal color
- value, i.e., 0 through COLORS-1, inclusive. The values
- that are stored at the addresses pointed to by the last
- three arguments are in the range 0 (no component) through
+ value, i.e., 0 through COLORS-1, inclusive. The values
+ that are stored at the addresses pointed to by the last
+ three arguments are in the range 0 (no component) through
1000 (maximum amount of component), inclusive.
- The pair_content routine allows programmers to find out
- what colors a given color-pair consists of. It requires
- three arguments: the color-pair number, and two addresses
- of shorts for storing the foreground and the background
- color numbers. The first argument must be a legal color
- value, i.e., in the range 1 through COLOR_PAIRS-1, inclu-
+ The pair_content routine allows programmers to find out
+ what colors a given color-pair consists of. It requires
+ three arguments: the color-pair number, and two addresses
+ of shorts for storing the foreground and the background
+ color numbers. The first argument must be a legal color
+ value, i.e., in the range 1 through COLOR_PAIRS-1, inclu-
sive. The values that are stored at the addresses pointed
- to by the second and third arguments are in the range 0
+ to by the second and third arguments are in the range 0
through COLORS, inclusive.
+ PAIR_NUMBER(attrs) extracts the color value from its attrs
+ parameter and returns it as a color pair number. Its in-
+ verse COLOR_PAIR(n) converts a color pair number to an at-
+ tribute. Attributes can hold color pairs in the range 0
+ to 255. If you need a color pair larger than that, you
+ must use functions such as attr_set (which pass the color
+ pair as a separate parameter) rather than the legacy func-
+ tions such as attrset.
-
-
+
+
In <curses.h> the following macros are defined. These are
- the default colors. curses also assumes that COLOR_BLACK
- is the default background color for all terminals.
+ the standard colors (ISO-6429). curses also assumes that
+ COLOR_BLACK is the default background color for all termi-
+ nals.
COLOR_BLACK
COLOR_RED
@@ -244,88 +301,84 @@
COLOR_WHITE
-
-
- The routines can_change_color() and has_colors() return
- TRUE or FALSE.
+
+ The routines can_change_color and has_colors return TRUE
+ or FALSE.
All other routines return the integer ERR upon failure and
- an OK (SVr4 specifies only "an integer value other than
+ an OK (SVr4 specifies only "an integer value other than
ERR") upon successful completion.
- X/Open defines no error conditions. This implementation
- will return ERR on attempts to use color values outside
+ X/Open defines no error conditions. This implementation
+ will return ERR on attempts to use color values outside
the range 0 to COLORS-1 (except for the default colors ex-
- tension), or use color pairs outside the range 0 to COL-
- OR_PAIRS-1. Color values used in init_color must be in
- the range 0 to 1000. An error is returned from all func-
- tions if the terminal has not been initialized. An error
- is returned from secondary functions such as init_pair if
+ tension), or use color pairs outside the range 0 to COL-
+ OR_PAIRS-1. Color values used in init_color must be in
+ the range 0 to 1000. An error is returned from all func-
+ tions if the terminal has not been initialized. An error
+ is returned from secondary functions such as init_pair if
start_color was not called.
init_color
- returns an error if the terminal does not support
- this feature, e.g., if the initialize_color capa-
+ returns an error if the terminal does not support
+ this feature, e.g., if the initialize_color capa-
bility is absent from the terminal description.
start_color
- returns an error if the color table cannot be al-
+ returns an error if the color table cannot be al-
located.
-
-
- In the ncurses implementation, there is a separate color
+
+ In the ncurses implementation, there is a separate color
activation flag, color palette, color pairs table, and as-
- sociated COLORS and COLOR_PAIRS counts for each screen;
- the start_color function only affects the current screen.
+ sociated COLORS and COLOR_PAIRS counts for each screen;
+ the start_color function only affects the current screen.
The SVr4/XSI interface is not really designed with this in
- mind, and historical implementations may use a single
+ mind, and historical implementations may use a single
shared color palette.
Note that setting an implicit background color via a color
- pair affects only character cells that a character write
- operation explicitly touches. To change the background
- color used when parts of a window are blanked by erasing
+ pair affects only character cells that a character write
+ operation explicitly touches. To change the background
+ color used when parts of a window are blanked by erasing
or scrolling operations, see curs_bkgd(3x).
- Several caveats apply on 386 and 486 machines with VGA-
+ Several caveats apply on 386 and 486 machines with VGA-
compatible graphics:
- o COLOR_YELLOW is actually brown. To get yellow, use
+ o COLOR_YELLOW is actually brown. To get yellow, use
COLOR_YELLOW combined with the A_BOLD attribute.
o The A_BLINK attribute should in theory cause the back-
- ground to go bright. This often fails to work, and
+ ground to go bright. This often fails to work, and
even some cards for which it mostly works (such as the
- Paradise and compatibles) do the wrong thing when you
- try to set a bright "yellow" background (you get a
+ Paradise and compatibles) do the wrong thing when you
+ try to set a bright "yellow" background (you get a
blinking yellow foreground instead).
o Color RGB values are not settable.
-
-
- This implementation satisfies XSI Curses's minimum maxi-
+
+ This implementation satisfies XSI Curses's minimum maxi-
mums for COLORS and COLOR_PAIRS.
- The init_pair routine accepts negative values of fore-
- ground and background color to support the use_de-
- fault_colors extension, but only if that routine has been
+ The init_pair routine accepts negative values of fore-
+ ground and background color to support the use_de-
+ fault_colors extension, but only if that routine has been
first invoked.
- The assumption that COLOR_BLACK is the default background
- color for all terminals can be modified using the as-
+ The assumption that COLOR_BLACK is the default background
+ color for all terminals can be modified using the as-
sume_default_colors extension.
- This implementation checks the pointers, e.g., for the
- values returned by color_content and pair_content, and
+ This implementation checks the pointers, e.g., for the
+ values returned by color_content and pair_content, and
will treat those as optional parameters when null.
-
-
+
curses(3x), curs_initscr(3x), curs_attr(3x), curs_vari-
ables(3x), default_colors(3x)
@@ -340,6 +393,7 @@
DESCRIPTION