X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fcurs_color.3x;h=965af772af654de3b6b9f3ef1abceb2cf873332f;hp=05288b5d835b5c9a5c955ecddb7f632e43129863;hb=97cb42f22c43eb31a4bf11475bd73ab0e0b10923;hpb=c3b21f65a2687f3894a0d3217006c23f162c893a diff --git a/man/curs_color.3x b/man/curs_color.3x index 05288b5d..965af772 100644 --- a/man/curs_color.3x +++ b/man/curs_color.3x @@ -1,5 +1,5 @@ .\"*************************************************************************** -.\" Copyright (c) 1998-2015,2016 Free Software Foundation, Inc. * +.\" Copyright (c) 1998-2018,2019 Free Software Foundation, Inc. * .\" * .\" Permission is hereby granted, free of charge, to any person obtaining a * .\" copy of this software and associated documentation files (the * @@ -26,29 +26,32 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: curs_color.3x,v 1.45 2016/10/15 17:10:19 tom Exp $ +.\" $Id: curs_color.3x,v 1.61 2019/01/20 17:04:08 tom Exp $ .TH curs_color 3X "" .ie \n(.g .ds `` \(lq .el .ds `` `` .ie \n(.g .ds '' \(rq .el .ds '' '' .de bP -.IP \(bu 4 +.ie n .IP \(bu 4 +.el .IP \(bu 2 .. .ds n 5 .na .hy 0 .SH NAME \fBstart_color\fR, -\fBinit_pair\fR, -\fBinit_color\fR, -.\" .br \fBhas_colors\fR, \fBcan_change_color\fR, -.\" .br +\fBinit_pair\fR, +\fBinit_color\fR, +\fBinit_extended_pair\fR, +\fBinit_extended_color\fR, \fBcolor_content\fR, \fBpair_content\fR, -.\" .br +\fBextended_color_content\fR, +\fBextended_pair_content\fR, +\fBreset_color_pairs\fR, \fBCOLOR_PAIR\fR, \fBPAIR_NUMBER\fR \- \fBcurses\fR color manipulation routines .ad @@ -57,18 +60,34 @@ \fB#include \fR .sp \fBint start_color(void);\fR +.sp +\fBbool has_colors(void);\fR .br +\fBbool can_change_color(void);\fR +.sp \fBint init_pair(short pair, short f, short b);\fR .br \fBint init_color(short color, short r, short g, short b);\fR -.sp -\fBbool has_colors(void);\fR .br -\fBbool can_change_color(void);\fR +/* extensions */ +.br +\fBint init_extended_pair(int pair, int f, int b);\fR +.br +\fBint init_extended_color(int color, int r, int g, int b);\fR .sp \fBint color_content(short color, short *r, short *g, short *b);\fR .br \fBint pair_content(short pair, short *f, short *b);\fR +.br +/* extensions */ +.br +\fBint extended_color_content(int color, int *r, int *g, int *b);\fR +.br +\fBint extended_pair_content(int pair, int *f, int *b);\fR +.sp +/* extensions */ +.br +\fBvoid reset_color_pairs(void);\fR .sp \fBint COLOR_PAIR(int n);\fR .br @@ -141,7 +160,35 @@ Some \fBcurses\fP functions such as \fBwprintw\fP call \fBwaddch\fP. Those do not combine its parameter with a color pair. Consequently those calls use only the window attribute or the background character. -.SS Routine Descriptions +.SH CONSTANTS +.PP +In \fB\fR the following macros are defined. +These are the standard colors (ISO-6429). +\fBcurses\fR also assumes that \fBCOLOR_BLACK\fR is the default +background color for all terminals. +.PP +.nf + \fBCOLOR_BLACK\fR + \fBCOLOR_RED\fR + \fBCOLOR_GREEN\fR + \fBCOLOR_YELLOW\fR + \fBCOLOR_BLUE\fR + \fBCOLOR_MAGENTA\fR + \fBCOLOR_CYAN\fR + \fBCOLOR_WHITE\fR +.fi +.PP +Some terminals support more than the eight (8) \*(``ANSI\*('' colors. +There are no standard names for those additional colors. +.SH VARIABLES +.SS COLORS +is initialized by \fBstart_color\fP to the maximum number of colors +the terminal can support. +.SS COLOR_PAIRS +is initialized by \fBstart_color\fP to the maximum number of color pairs +the terminal can support. +.SH FUNCTIONS +.SS start_color The \fBstart_color\fR routine requires no arguments. It must be called if the programmer wants to use colors, and before any other color manipulation routine is called. @@ -162,15 +209,24 @@ they had when the terminal was just turned on. If the terminal supports the \fBinitc\fP (\fBinitialize_color\fP) capability, \fBstart_color\fP initializes its internal table representing the -red, green and blue components of the color palette. +red, green, and blue components of the color palette. .IP The components depend on whether the terminal uses -CGA (aka \*(lqANSI\*(rq) or +CGA (aka \*(``ANSI\*('') or HLS (i.e., the \fBhls\fP (\fBhue_lightness_saturation\fP) capability is set). The table is initialized first for eight basic colors (black, red, green, yellow, blue, magenta, cyan, and white), -and after that (if the terminal supports more than eight colors) -the components are initialized to \fB1000\fP. +using weights that depend upon the CGA/HLS choice. +For \*(``ANSI\*('' colors the weights are \fB680\fP or \fB0\fP +depending on whether the corresponding +red, green, or blue component is used or not. +That permits using \fB1000\fP to represent bold/bright colors. +After the initial eight colors +(if the terminal supports more than eight colors) +the components are initialized using the same pattern, +but with weights of \fB1000\fP. +SVr4 uses a similar scheme, but uses \fB1000\fP +for the components of the initial eight colors. .IP \fBstart_color\fP does not attempt to set the terminal's color palette to match its built-in table. @@ -180,17 +236,18 @@ along with the terminal's color. These limits apply to color values and color pairs. Values outside these limits are not legal, and may result in a runtime error: .bP -\fBCOLORS\fP corresponds to the terminal database's \fBmax_colors\fP capability, -which is typically a signed 16-bit integer (see \fBterminfo\fR(\*n)). +\fBCOLORS\fP corresponds to the terminal database's \fBmax_colors\fR capability, +(see \fBterminfo\fR(\*n)). .bP color values are expected to be in the range \fB0\fP to \fBCOLORS\-1\fP, inclusive (including \fB0\fP and \fBCOLORS\-1\fP). .bP a special color value \fB\-1\fP is used in certain extended functions -to denote the \fIdefault color\fP (see \fBuse_default_colors\fP). +to denote the \fIdefault color\fP (see \fBuse_default_colors\fP(3X)). .bP -\fBCOLOR_PAIRS\fP corresponds to the terminal database's \fBmax_pairs\fP capability, -which is typically a signed 16-bit integer (see \fBterminfo\fR(\*n)). +\fBCOLOR_PAIRS\fP corresponds to +the terminal database's \fBmax_pairs\fP capability, +(see \fBterminfo\fR(\*n)). .bP legal color pair values are in the range \fB1\fP to \fBCOLOR_PAIRS\-1\fP, inclusive. @@ -200,14 +257,31 @@ color pair \fB0\fP is special; it denotes \*(``no color\*(''. Color pair \fB0\fP 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. +.SS has_colors +.PP +The \fBhas_colors\fR routine requires no arguments. +It returns \fBTRUE\fR if +the terminal can manipulate colors; otherwise, it returns \fBFALSE\fR. +This routine facilitates writing terminal-independent programs. +For example, a programmer can use it to decide +whether to use color or some other video attribute. +.SS can_change_color +.PP +The \fBcan_change_color\fR routine requires no arguments. +It returns \fBTRUE\fR if the terminal supports colors +and can change their definitions; +other, it returns \fBFALSE\fR. +This routine facilitates writing terminal-independent programs. +.SS init_pair .PP The \fBinit_pair\fR routine changes the definition of a color-pair. -It takes three arguments: the number of the color-pair to be changed, the foreground +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: .bP The first argument must be a legal color pair value. -If default colors are used (see \fBuse_default_colors\fP) +If default colors are used (see \fBuse_default_colors\fP(3X)) the upper limit is adjusted to allow for extra pairs which use a default color in foreground and/or background. .bP @@ -218,34 +292,44 @@ the screen is refreshed and all occurrences of that color-pair are changed to the new definition. .PP As an extension, ncurses allows you to set color pair \fB0\fP via -the \fBassume_default_colors\fR routine, or to specify the use of +the \fBassume_default_colors\fR(3X) routine, or to specify the use of default colors (color number \fB\-1\fR) if you first invoke the -\fBuse_default_colors\fR routine. +\fBuse_default_colors\fR(3X) routine. +.SS init_extended_pair +.PP +Because \fBinit_pair\fP uses signed \fBshort\fPs for its parameters, +that limits color-pairs and color-values +to 32767 on modern hardware. +The extension \fBinit_extended_pair\fP uses \fBint\fPs +for the color-pair and color-value, +allowing a larger number of colors to be supported. +.SS init_color .PP The \fBinit_color\fR routine changes the definition of a color. -It takes four arguments: the number of the color to be changed followed by three RGB values +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). +.bP The first argument must be a legal color value; default colors are not allowed here. (See the section \fBColors\fR for the default color index.) +.bP Each of the last three arguments must be a value in the range \fB0\fP through \fB1000\fP. +.PP When \fBinit_color\fR is used, all occurrences of that color on the screen immediately change to the new definition. +.SS init_extended_color .PP -The \fBhas_colors\fR routine requires no arguments. -It returns \fBTRUE\fR if -the terminal can manipulate colors; otherwise, it returns \fBFALSE\fR. -This routine facilitates writing terminal-independent programs. -For example, a programmer can use it to decide -whether to use color or some other video attribute. -.PP -The \fBcan_change_color\fR routine requires no arguments. -It returns \fBTRUE\fR if the terminal supports colors -and can change their definitions; -other, it returns \fBFALSE\fR. -This routine facilitates writing terminal-independent programs. +Because \fBinit_color\fP uses signed \fBshort\fPs for its parameters, +that limits color-values and their red, green, and blue components +to 32767 on modern hardware. +The extension \fBinit_extended_color\fP uses \fBint\fPs +for the color value and +for setting the red, green, and blue components, +allowing a larger number of colors to be supported. +.SS color_content .PP The \fBcolor_content\fR routine gives programmers a way to find the intensity of the red, green, and blue (RGB) components in a color. @@ -253,65 +337,97 @@ It requires four arguments: the color number, and three addresses of \fBshort\fRs for storing the information about the amounts of red, green, and blue components in the given color. +.bP The first argument must be a legal color value, i.e., \fB0\fP through \fBCOLORS\-1\fP, inclusive. +.bP The values that are stored at the addresses pointed to by the last three arguments are in the range -\fB0\fP (no component) through \fB1000\fP (maximum amount of component), inclusive. +\fB0\fP (no component) through \fB1000\fP +(maximum amount of component), inclusive. +.SS extended_color_content +.PP +Because \fBcolor_content\fP uses signed \fBshort\fPs for its parameters, +that limits color-values and their red, green, and blue components +to 32767 on modern hardware. +The extension \fBextended_color_content\fP uses \fBint\fPs +for the color value and +for returning the red, green, and blue components, +allowing a larger number of colors to be supported. +.SS pair_content .PP The \fBpair_content\fR 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 \fBshort\fRs for storing the foreground and the background color numbers. +.bP The first argument must be a legal color value, i.e., in the range \fB1\fP through \fBCOLOR_PAIRS\-1\fR, inclusive. +.bP The values that are stored at the addresses pointed to by the second and third arguments are in the range \fB0\fP through \fBCOLORS\fR, inclusive. +.SS extended_pair_content +.PP +Because \fBpair_content\fP uses signed \fBshort\fPs for its parameters, +that limits color-pair and color-values to 32767 on modern hardware. +The extension \fBextended_pair_content\fP uses \fBint\fPs +for the color pair and +for returning the foreground and background colors, +allowing a larger number of colors to be supported. +.SS reset_color_pairs +.PP +The extension \fBreset_color_pairs\fP tells ncurses to discard all +of the color-pair information which was set with \fBinit_pair\fP. +It also touches the current- and standard-screens, allowing an application to +switch color palettes rapidly. +.SS PAIR_NUMBER .PP \fBPAIR_NUMBER(\fR\fIattrs\fR) extracts the color value from its \fIattrs\fP parameter and returns it as a color pair number. +.SS COLOR_PAIR Its inverse \fBCOLOR_PAIR(\fR\fIn\fR\fB)\fR converts a color pair number to an attribute. 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 \fBattr_set\fP (which pass the color pair as a separate parameter) rather than the legacy functions such as \fBattrset\fP. -.SS Colors -In \fB\fR the following macros are defined. -These are the standard colors (ISO-6429). -\fBcurses\fR also assumes that \fBCOLOR_BLACK\fR is the default -background color for all terminals. -.PP -.nf - \fBCOLOR_BLACK\fR - \fBCOLOR_RED\fR - \fBCOLOR_GREEN\fR - \fBCOLOR_YELLOW\fR - \fBCOLOR_BLUE\fR - \fBCOLOR_MAGENTA\fR - \fBCOLOR_CYAN\fR - \fBCOLOR_WHITE\fR -.fi .SH RETURN VALUE The routines \fBcan_change_color\fR and \fBhas_colors\fR return \fBTRUE\fR or \fBFALSE\fR. .PP All other routines return the integer \fBERR\fR upon failure and an \fBOK\fR -(SVr4 specifies only \*(lqan integer value other than \fBERR\fR\*(rq) upon successful -completion. +(SVr4 specifies only \*(``an integer value +other than \fBERR\fR\*('') upon successful completion. .PP X/Open defines no error conditions. +SVr4 does document some error conditions which apply in general: +.bP This implementation will return \fBERR\fR on attempts to -use color values outside the range \fB0\fP to COLORS\-1 +use color values outside the range \fB0\fP to \fBCOLORS\fP\-1 (except for the default colors extension), or use color pairs outside the range \fB0\fP to \fBCOLOR_PAIRS\-1\fP. -Color values used in \fBinit_color\fP must be in the range \fB0\fP to \fB1000\fP. +.IP +Color values used in \fBinit_color\fP must be +in the range \fB0\fP to \fB1000\fP. +.IP An error is returned from all functions if the terminal has not been initialized. +.IP An error is returned from secondary functions such as \fBinit_pair\fP if \fBstart_color\fP was not called. +.bP +SVr4 does much the same, except that +it returns \fBERR\fP from \fBpair_content\fP if the pair was not initialized +using \fBinit_pairs\fP +and +it returns \fBERR\fP from \fBcolor_content\fP +if the terminal does not support changing colors. +.IP +This implementation does not return \fBERR\fP for either case. +.PP +Specific functions make additional checks: .RS 3 .TP 5 \fBinit_color\fP @@ -323,20 +439,22 @@ from the terminal description. returns an error if the color table cannot be allocated. .RE .SH NOTES -In the \fIncurses\fR implementation, there is a separate color activation flag, -color palette, color pairs table, and associated COLORS and COLOR_PAIRS counts +In the \fBncurses\fR implementation, there is a separate color activation flag, +color palette, color pairs table, +and associated \fBCOLORS\fP and \fBCOLOR_PAIRS\fP counts for each screen; the \fBstart_color\fR 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. .PP -Note that setting an implicit background color via a color pair affects only +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 \fBcurs_bkgd\fR(3X). .PP -Several caveats apply on 386 and 486 machines with VGA-compatible graphics: +Several caveats apply on older x86 machines +(e.g., i386, i486) with VGA-compatible graphics: .bP COLOR_YELLOW is actually brown. To get yellow, use COLOR_YELLOW combined with the \fBA_BOLD\fR attribute. @@ -345,7 +463,7 @@ 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 -\*(lqyellow\*(rq background (you get a blinking yellow foreground instead). +\*(``yellow\*('' background (you get a blinking yellow foreground instead). .bP Color RGB values are not settable. .SH PORTABILITY @@ -353,17 +471,28 @@ This implementation satisfies XSI Curses's minimum maximums for \fBCOLORS\fR and \fBCOLOR_PAIRS\fR. .PP The \fBinit_pair\fP routine accepts negative values of foreground -and background color to support the \fBuse_default_colors\fP extension, +and background color to support the \fBuse_default_colors\fR(3X) extension, but only if that routine has been first invoked. .PP The assumption that \fBCOLOR_BLACK\fR is the default background color for all terminals can be modified using the -\fBassume_default_colors\fP extension. +\fBassume_default_colors\fR(3X) extension. .PP This implementation checks the pointers, e.g., for the values returned by \fBcolor_content\fP and \fBpair_content\fP, and will treat those as optional parameters when null. +.PP +X/Open Curses does not specify a limit for the number of colors and +color pairs which a terminal can support. +However, in its use of \fBshort\fP for the parameters, +it carries over SVr4's implementation detail for the compiled +terminfo database, which uses signed 16-bit numbers. +This implementation provides extended versions of those functions +which use \fBshort\fP parameters, +allowing applications to use larger color- and pair-numbers. +.PP +The \fBreset_color_pairs\fP function is an extension of ncurses. .SH SEE ALSO \fBcurses\fR(3X), \fBcurs_initscr\fR(3X),