1 <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
3 ****************************************************************************
4 * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc. *
6 * Permission is hereby granted, free of charge, to any person obtaining a *
7 * copy of this software and associated documentation files (the *
8 * "Software"), to deal in the Software without restriction, including *
9 * without limitation the rights to use, copy, modify, merge, publish, *
10 * distribute, distribute with modifications, sublicense, and/or sell *
11 * copies of the Software, and to permit persons to whom the Software is *
12 * furnished to do so, subject to the following conditions: *
14 * The above copyright notice and this permission notice shall be included *
15 * in all copies or substantial portions of the Software. *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
20 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
23 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
25 * Except as contained in this notice, the name(s) of the above copyright *
26 * holders shall not be used in advertising or otherwise to promote the *
27 * sale, use or other dealings in this Software without prior written *
29 ****************************************************************************
30 * @Id: curs_color.3x,v 1.30 2010/07/31 16:12:01 tom Exp @
34 <TITLE>curs_color 3x</TITLE>
35 <link rev=made href="mailto:bug-ncurses@gnu.org">
36 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
39 <H1>curs_color 3x</H1>
42 <!-- Manpage converted by man2html 3.0.1 -->
43 <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
50 <STRONG>start_color</STRONG>, <STRONG>init_pair</STRONG>, <STRONG>init_color</STRONG>, <STRONG>has_colors</STRONG>,
51 <STRONG>can_change_color</STRONG>, <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>, <STRONG>COLOR_PAIR</STRONG>
52 - <STRONG>curses</STRONG> color manipulation routines
56 <H2>SYNOPSIS</H2><PRE>
57 <STRONG>#</STRONG> <STRONG>include</STRONG> <STRONG><curses.h></STRONG>
58 <STRONG>int</STRONG> <STRONG>start_color(void);</STRONG>
59 <STRONG>int</STRONG> <STRONG>init_pair(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>f,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
60 <STRONG>int</STRONG> <STRONG>init_color(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>r,</STRONG> <STRONG>short</STRONG> <STRONG>g,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
61 <STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG>
62 <STRONG>bool</STRONG> <STRONG>can_change_color(void);</STRONG>
63 <STRONG>int</STRONG> <STRONG>color_content(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>*r,</STRONG> <STRONG>short</STRONG> <STRONG>*g,</STRONG> <STRONG>short</STRONG>
65 <STRONG>int</STRONG> <STRONG>pair_content(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>*f,</STRONG> <STRONG>short</STRONG> <STRONG>*b);</STRONG>
69 <H2>DESCRIPTION</H2><PRE>
70 <STRONG>Overview</STRONG>
71 <STRONG>curses</STRONG> support color attributes on terminals with that ca-
72 pability. To use these routines <STRONG>start_color</STRONG> must be
73 called, usually right after <STRONG>initscr</STRONG>. Colors are always
74 used in pairs (referred to as color-pairs). A color-pair
75 consists of a foreground color (for characters) and a
76 background color (for the blank field on which the charac-
77 ters are displayed). A programmer initializes a color-
78 pair with the routine <STRONG>init_pair</STRONG>. After it has been ini-
79 tialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>), a macro defined in <STRONG><curses.h></STRONG>,
80 can be used as a new video attribute.
82 If a terminal is capable of redefining colors, the pro-
83 grammer can use the routine <STRONG>init_color</STRONG> to change the defi-
84 nition of a color. The routines <STRONG>has_colors</STRONG> and
85 <STRONG>can_change_color</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>, depending on
86 whether the terminal has color capabilities and whether
87 the programmer can change the colors. The routine <STRONG>col-</STRONG>
88 <STRONG>or_content</STRONG> allows a programmer to extract the amounts of
89 red, green, and blue components in an initialized color.
90 The routine <STRONG>pair_content</STRONG> allows a programmer to find out
91 how a given color-pair is currently defined.
93 <STRONG>Routine</STRONG> <STRONG>Descriptions</STRONG>
94 The <STRONG>start_color</STRONG> routine requires no arguments. It must be
95 called if the programmer wants to use colors, and before
96 any other color manipulation routine is called. It is
97 good practice to call this routine right after <STRONG>initscr</STRONG>.
98 <STRONG>start_color</STRONG> initializes eight basic colors (black, red,
99 green, yellow, blue, magenta, cyan, and white), and two
100 global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (respectively
101 defining the maximum number of colors and color-pairs the
102 terminal can support). It also restores the colors on the
103 terminal to the values they had when the terminal was just
106 The <STRONG>init_pair</STRONG> routine changes the definition of a color-
107 pair. It takes three arguments: the number of the color-
108 pair to be changed, the foreground color number, and the
109 background color number. For portable applications:
111 - The value of the first argument must be between <STRONG>1</STRONG> and
112 <STRONG>COLOR_PAIRS-1</STRONG>, except that if default colors are used
113 (see <STRONG>use_default_colors</STRONG>) the upper limit is adjusted
114 to allow for extra pairs which use a default color in
115 foreground and/or background.
117 - The value of the second and third arguments must be
118 between 0 and <STRONG>COLORS</STRONG>. Color pair 0 is assumed to be
119 white on black, but is actually whatever the terminal
120 implements before color is initialized. It cannot be
121 modified by the application.
123 If the color-pair was previously initialized, the screen
124 is refreshed and all occurrences of that color-pair are
125 changed to the new definition.
127 As an extension, ncurses allows you to set color pair 0
128 via the <STRONG>assume_default_colors</STRONG> routine, or to specify the
129 use of default colors (color number <STRONG>-1</STRONG>) if you first in-
130 voke the <STRONG>use_default_colors</STRONG> routine.
132 The <STRONG>init_color</STRONG> routine changes the definition of a color.
133 It takes four arguments: the number of the color to be
134 changed followed by three RGB values (for the amounts of
135 red, green, and blue components). The value of the first
136 argument must be between <STRONG>0</STRONG> and <STRONG>COLORS</STRONG>. (See the section
137 <STRONG>Colors</STRONG> for the default color index.) Each of the last
138 three arguments must be a value between 0 and 1000. When
139 <STRONG>init_color</STRONG> is used, all occurrences of that color on the
140 screen immediately change to the new definition.
142 The <STRONG>has_colors</STRONG> routine requires no arguments. It returns
143 <STRONG>TRUE</STRONG> if the terminal can manipulate colors; otherwise, it
144 returns <STRONG>FALSE</STRONG>. This routine facilitates writing terminal-
145 independent programs. For example, a programmer can use
146 it to decide whether to use color or some other video at-
149 The <STRONG>can_change_color</STRONG> routine requires no arguments. It
150 returns <STRONG>TRUE</STRONG> if the terminal supports colors and can
151 change their definitions; other, it returns <STRONG>FALSE</STRONG>. This
152 routine facilitates writing terminal-independent programs.
154 The <STRONG>color_content</STRONG> routine gives programmers a way to find
155 the intensity of the red, green, and blue (RGB) components
156 in a color. It requires four arguments: the color number,
157 and three addresses of <STRONG>short</STRONG>s for storing the information
158 about the amounts of red, green, and blue components in
159 the given color. The value of the first argument must be
160 between 0 and <STRONG>COLORS</STRONG>. The values that are stored at the
161 addresses pointed to by the last three arguments are be-
162 tween 0 (no component) and 1000 (maximum amount of compo-
165 The <STRONG>pair_content</STRONG> routine allows programmers to find out
166 what colors a given color-pair consists of. It requires
167 three arguments: the color-pair number, and two addresses
168 of <STRONG>short</STRONG>s for storing the foreground and the background
169 color numbers. The value of the first argument must be
170 between 1 and <STRONG>COLOR_PAIRS-1</STRONG>. The values that are stored
171 at the addresses pointed to by the second and third argu-
172 ments are between 0 and <STRONG>COLORS</STRONG>.
174 <STRONG>Colors</STRONG>
175 In <STRONG><curses.h></STRONG> the following macros are defined. These are
176 the default colors. <STRONG>curses</STRONG> also assumes that <STRONG>COLOR_BLACK</STRONG>
177 is the default background color for all terminals.
179 <STRONG>COLOR_BLACK</STRONG>
180 <STRONG>COLOR_RED</STRONG>
181 <STRONG>COLOR_GREEN</STRONG>
182 <STRONG>COLOR_YELLOW</STRONG>
183 <STRONG>COLOR_BLUE</STRONG>
184 <STRONG>COLOR_MAGENTA</STRONG>
185 <STRONG>COLOR_CYAN</STRONG>
186 <STRONG>COLOR_WHITE</STRONG>
190 <H2>RETURN VALUE</H2><PRE>
191 The routines <STRONG>can_change_color()</STRONG> and <STRONG>has_colors()</STRONG> return
192 <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>.
194 All other routines return the integer <STRONG>ERR</STRONG> upon failure and
195 an <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than
196 <STRONG>ERR</STRONG>") upon successful completion.
198 X/Open defines no error conditions. This implementation
199 will return <STRONG>ERR</STRONG> on attempts to use color values outside
200 the range 0 to COLORS-1 (except for the default colors ex-
201 tension), or use color pairs outside the range 0 to COL-
202 OR_PAIR-1. Color values used in <STRONG>init_color</STRONG> must be in the
203 range 0 to 1000. An error is returned from all functions
204 if the terminal has not been initialized. An error is re-
205 turned from secondary functions such as <STRONG>init_pair</STRONG> if
206 <STRONG>start_color</STRONG> was not called.
208 <STRONG>init_color</STRONG>
209 returns an error if the terminal does not sup-
210 port this feature, e.g., if the <EM>initial-</EM>
211 <EM>ize</EM><STRONG>_</STRONG><EM>color</EM> capability is absent from the termi-
214 <STRONG>start_color</STRONG>
215 returns an error If the color table cannot be
221 In the <EM>ncurses</EM> implementation, there is a separate color
222 activation flag, color palette, color pairs table, and as-
223 sociated COLORS and COLOR_PAIRS counts for each screen;
224 the <STRONG>start_color</STRONG> function only affects the current screen.
225 The SVr4/XSI interface is not really designed with this in
226 mind, and historical implementations may use a single
227 shared color palette.
229 Note that setting an implicit background color via a color
230 pair affects only character cells that a character write
231 operation explicitly touches. To change the background
232 color used when parts of a window are blanked by erasing
233 or scrolling operations, see <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
235 Several caveats apply on 386 and 486 machines with VGA-
238 - COLOR_YELLOW is actually brown. To get yellow, use
239 COLOR_YELLOW combined with the <STRONG>A_BOLD</STRONG> attribute.
241 - The A_BLINK attribute should in theory cause the
242 background to go bright. This often fails to work,
243 and even some cards for which it mostly works (such
244 as the Paradise and compatibles) do the wrong thing
245 when you try to set a bright "yellow" background (you
246 get a blinking yellow foreground instead).
248 - Color RGB values are not settable.
252 <H2>PORTABILITY</H2><PRE>
253 This implementation satisfies XSI Curses's minimum maxi-
254 mums for <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG>.
256 The <STRONG>init_pair</STRONG> routine accepts negative values of fore-
257 ground and background color to support the <STRONG>use_de-</STRONG>
258 <STRONG>fault_colors</STRONG> extension, but only if that routine has been
261 The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background
262 color for all terminals can be modified using the <STRONG>as-</STRONG>
263 <STRONG>sume_default_colors</STRONG> extension.
265 This implementation checks the pointers, e.g., for the
266 values returned by <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG>, and
267 will treat those as optional parameters when null.
271 <H2>SEE ALSO</H2><PRE>
272 <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>
273 <STRONG><A HREF="default_colors.3x.html">ors(3x)</A></STRONG>
277 <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
281 Man(1) output converted with
282 <a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>