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ters are displayed). A programmer initializes a color-
pair with the routine <STRONG>init_pair</STRONG>. After it has been ini-
tialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>), a macro defined in <STRONG><curses.h></STRONG>,
- can be used as a new video attribute. If a terminal is
- capable of redefining colors, the programmer can use the
- routine <STRONG>init_color</STRONG> to change the definition of a color.
- The routines <STRONG>has_colors</STRONG> and <STRONG>can_change_color</STRONG> return <STRONG>TRUE</STRONG>
- or <STRONG>FALSE</STRONG>, depending on whether the terminal has color ca-
- pabilities and whether the programmer can change the col-
- ors. The routine <STRONG>color_content</STRONG> allows a programmer to ex-
- tract the amounts of red, green, and blue components in an
- initialized color. The routine <STRONG>pair_content</STRONG> allows a pro-
- grammer to find out how a given color-pair is currently
- defined.
+ can be used as a new video attribute.
+
+ If a terminal is capable of redefining colors, the pro-
+ grammer can use the routine <STRONG>init_color</STRONG> to change the defi-
+ nition of a color. The routines <STRONG>has_colors</STRONG> and
+ <STRONG>can_change_color</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>, depending on
+ whether the terminal has color capabilities and whether
+ the programmer can change the colors. The routine <STRONG>col-</STRONG>
+ <STRONG>or_content</STRONG> allows a programmer to extract the amounts of
+ red, green, and blue components in an initialized color.
+ The routine <STRONG>pair_content</STRONG> allows a programmer to find out
+ how a given color-pair is currently defined.
<STRONG>Routine</STRONG> <STRONG>Descriptions</STRONG>
The <STRONG>start_color</STRONG> 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 <STRONG>initscr</STRONG>.
- <STRONG>start_color</STRONG> initializes eight basic colors (black, red,
- green, yellow, blue, magenta, cyan, and white), and two
- global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (respectively
- defining the maximum number of colors and color-pairs the
+ 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 <STRONG>initscr</STRONG>.
+ <STRONG>start_color</STRONG> initializes eight basic colors (black, red,
+ green, yellow, blue, magenta, cyan, and white), and two
+ global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (respectively
+ defining the maximum number of colors and color-pairs the
terminal can support). It also restores the colors on the
terminal to the values they had when the terminal was just
- turned on. The <STRONG>init_pair</STRONG> 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 applica-
- tions:
+ turned on.
+
+ The <STRONG>init_pair</STRONG> 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:
- The value of the first argument must be between <STRONG>1</STRONG> and
- <STRONG>COLOR_PAIRS-1</STRONG>.
+ <STRONG>COLOR_PAIRS-1</STRONG>, except that if default colors are used
+ (see <STRONG>use_default_colors</STRONG>) the upper limit is adjusted
+ to allow for extra pairs which use a default color in
+ foreground and/or background.
- - The value of the second and third arguments must be
- between 0 and <STRONG>COLORS</STRONG>. Color pair 0 is assumed to be
+ - The value of the second and third arguments must be
+ between 0 and <STRONG>COLORS</STRONG>. 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 application.
- 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 <STRONG>assume_default_col-</STRONG>
- <STRONG>ors</STRONG> routine, or to specify the use of default colors (col-
- or number <STRONG>-1</STRONG>) if you first invoke the <STRONG>use_default_colors</STRONG>
- routine. The <STRONG>init_color</STRONG> 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 value of
- the first argument must be between <STRONG>0</STRONG> and <STRONG>COLORS</STRONG>. (See the
- section <STRONG>Colors</STRONG> for the default color index.) Each of the
- last three arguments must be a value between 0 and 1000.
- When <STRONG>init_color</STRONG> is used, all occurrences of that color on
- the screen immediately change to the new definition. The
- <STRONG>has_colors</STRONG> routine requires no arguments. It returns <STRONG>TRUE</STRONG>
- if the terminal can manipulate colors; otherwise, it re-
- turns <STRONG>FALSE</STRONG>. 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-
- tribute. The <STRONG>can_change_color</STRONG> routine requires no argu-
- ments. It returns <STRONG>TRUE</STRONG> if the terminal supports colors
- and can change their definitions; other, it returns <STRONG>FALSE</STRONG>.
- This routine facilitates writing terminal-independent pro-
- grams. The <STRONG>color_content</STRONG> 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 <STRONG>short</STRONG>s for storing
- the information about the amounts of red, green, and blue
- components in the given color. The value of the first ar-
- gument must be between 0 and <STRONG>COLORS</STRONG>. The values that are
- stored at the addresses pointed to by the last three argu-
- ments are between 0 (no component) and 1000 (maximum
- amount of component). The <STRONG>pair_content</STRONG> 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 <STRONG>short</STRONG>s for storing the fore-
- ground and the background color numbers. The value of the
- first argument must be between 1 and <STRONG>COLOR_PAIRS-1</STRONG>. The
- values that are stored at the addresses pointed to by the
- second and third arguments are between 0 and <STRONG>COLORS</STRONG>.
+ 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 <STRONG>assume_default_colors</STRONG> routine, or to specify the
+ use of default colors (color number <STRONG>-1</STRONG>) if you first in-
+ voke the <STRONG>use_default_colors</STRONG> routine.
+
+ The <STRONG>init_color</STRONG> 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 value of the first
+ argument must be between <STRONG>0</STRONG> and <STRONG>COLORS</STRONG>. (See the section
+ <STRONG>Colors</STRONG> for the default color index.) Each of the last
+ three arguments must be a value between 0 and 1000. When
+ <STRONG>init_color</STRONG> is used, all occurrences of that color on the
+ screen immediately change to the new definition.
+
+ The <STRONG>has_colors</STRONG> routine requires no arguments. It returns
+ <STRONG>TRUE</STRONG> if the terminal can manipulate colors; otherwise, it
+ returns <STRONG>FALSE</STRONG>. 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-
+ tribute.
+
+ The <STRONG>can_change_color</STRONG> routine requires no arguments. It
+ returns <STRONG>TRUE</STRONG> if the terminal supports colors and can
+ change their definitions; other, it returns <STRONG>FALSE</STRONG>. This
+ routine facilitates writing terminal-independent programs.
+
+ The <STRONG>color_content</STRONG> 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 <STRONG>short</STRONG>s for storing the information
+ about the amounts of red, green, and blue components in
+ the given color. The value of the first argument must be
+ between 0 and <STRONG>COLORS</STRONG>. The values that are stored at the
+ addresses pointed to by the last three arguments are be-
+ tween 0 (no component) and 1000 (maximum amount of compo-
+ nent).
+
+ The <STRONG>pair_content</STRONG> 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 <STRONG>short</STRONG>s for storing the foreground and the background
+ color numbers. The value of the first argument must be
+ between 1 and <STRONG>COLOR_PAIRS-1</STRONG>. The values that are stored
+ at the addresses pointed to by the second and third argu-
+ ments are between 0 and <STRONG>COLORS</STRONG>.
<STRONG>Colors</STRONG>
In <STRONG><curses.h></STRONG> the following macros are defined. These are
the default colors. <STRONG>curses</STRONG> also assumes that <STRONG>COLOR_BLACK</STRONG>
is the default background color for all terminals.
+
<STRONG>COLOR_BLACK</STRONG>
<STRONG>COLOR_RED</STRONG>
<STRONG>COLOR_GREEN</STRONG>
</PRE>
<H2>RETURN VALUE</H2><PRE>
The routines <STRONG>can_change_color()</STRONG> and <STRONG>has_colors()</STRONG> return
- <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>. All other routines return the integer <STRONG>ERR</STRONG>
- upon failure and an <STRONG>OK</STRONG> (SVr4 specifies only "an integer
- value other than <STRONG>ERR</STRONG>") upon successful completion.
+ <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>.
+
+ All other routines return the integer <STRONG>ERR</STRONG> upon failure and
+ an <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than
+ <STRONG>ERR</STRONG>") upon successful completion.
X/Open defines no error conditions. This implementation
will return <STRONG>ERR</STRONG> on attempts to use color values outside
the <STRONG>start_color</STRONG> 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
- shared color palette. Note that setting an implicit back-
- ground 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 or scrolling operations, see
- <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>. Several caveats apply on 386 and 486 ma-
- chines with VGA-compatible graphics:
-
- - COLOR_YELLOW is actually brown. To get yellow, use
+ 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
+ or scrolling operations, see <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
+
+ Several caveats apply on 386 and 486 machines with VGA-
+ compatible graphics:
+
+ - COLOR_YELLOW is actually brown. To get yellow, use
COLOR_YELLOW combined with the <STRONG>A_BOLD</STRONG> attribute.
- - The A_BLINK attribute should in theory cause the
- background 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
+ - The A_BLINK attribute should in theory cause the
+ background 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 blinking yellow foreground instead).
</PRE>
<H2>PORTABILITY</H2><PRE>
- This implementation satisfies XSI Curses's minimum maxi-
+ This implementation satisfies XSI Curses's minimum maxi-
mums for <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG>.
- The <STRONG>init_pair</STRONG> routine accepts negative values of fore-
- ground and background color to support the <STRONG>use_de-</STRONG>
- <STRONG>fault_colors</STRONG> extension, but only if that routine has been
+ The <STRONG>init_pair</STRONG> routine accepts negative values of fore-
+ ground and background color to support the <STRONG>use_de-</STRONG>
+ <STRONG>fault_colors</STRONG> extension, but only if that routine has been
first invoked.
- The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background
- color for all terminals can be modified using the <STRONG>as-</STRONG>
+ The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background
+ color for all terminals can be modified using the <STRONG>as-</STRONG>
<STRONG>sume_default_colors</STRONG> extension.
- This implementation checks the pointers, e.g., for the
- values returned by <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG>, and
+ This implementation checks the pointers, e.g., for the
+ values returned by <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG>, and
will treat those as optional parameters when null.
</PRE>
<H2>SEE ALSO</H2><PRE>
- <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG>default_col-</STRONG>
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG>default_col-</STRONG>
<STRONG><A HREF="default_colors.3x.html">ors(3x)</A></STRONG>