X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_color.3x.html;h=bab33b328c15d3f8d2d0aa4c86ba319188932f52;hp=8840f1dfe6fc1bfe75813d2ff0b02c357051f7c5;hb=3eda6f30a84d53844d2ebceadb457e2e7e9cfbf3;hpb=55ccd2b959766810cf7db8d1c4462f338ce0afc8 diff --git a/doc/html/man/curs_color.3x.html b/doc/html/man/curs_color.3x.html index 8840f1df..bab33b32 100644 --- a/doc/html/man/curs_color.3x.html +++ b/doc/html/man/curs_color.3x.html @@ -1,7 +1,6 @@ - +
+ +- curs_color(3x) curs_color(3x) --
- start_color, init_pair, init_color, has_colors, - can_change_color, color_content, pair_content, COLOR_PAIR - - curses color manipulation routines +
+ start_color, has_colors, can_change_color, init_pair, + init_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 init_pair(short pair, short f, short b); + int init_color(short color, short r, short g, short b); + /* extensions */ + int init_extended_pair(int pair, int f, int b); + int init_extended_color(int color, int r, int g, int b); + int color_content(short color, short *r, short *g, short *b); int pair_content(short pair, short *f, short *b); + /* extensions */ + int extended_color_content(int color, int *r, int *g, int + *b); + int extended_pair_content(int pair, int *f, int *b); + int COLOR_PAIR(int n); + PAIR_NUMBER(attrs); --
- Overview - curses support color attributes on terminals with that ca- - pability. 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 + +
+ +
+ 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. If a terminal is - capable of redefining colors, the programmer can use the - routine init_color to change the definition of a color. - The routines has_colors and can_change_color return TRUE - or FALSE, depending on whether the terminal has color ca- - pabilities and whether the programmer can change the col- - ors. The routine color_content allows a programmer to ex- - tract the amounts of red, green, and blue components in an - initialized color. The routine pair_content allows a pro- - grammer to find out how a given color-pair is currently - defined. - - Routine Descriptions - 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. - start_color initializes eight basic colors (black, red, - green, yellow, blue, magenta, cyan, and white), and two - global variables, COLORS and COLOR_PAIRS (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 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 applica- - tions: - - - The value of the first argument must be between 1 and - COLOR_PAIRS-1. - - - The value of the second and third arguments must be - between 0 and COLORS. 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 assume_default_col- - ors routine, or to specify the use of default colors (col- - or number -1) if you first invoke 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 red, green, and blue components). The value of - the first argument must be between 0 and COLORS. (See the - section Colors for the default color index.) Each of the - last three arguments must be a value between 0 and 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 re- - turns 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- - tribute. The can_change_color routine requires no argu- - ments. It returns TRUE if the terminal supports colors - and can change their definitions; other, it returns FALSE. - This routine facilitates writing terminal-independent pro- - grams. 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 the given color. The value of the first ar- - gument must be between 0 and COLORS. 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 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 fore- - ground and the background color numbers. The value of the - first argument must be between 1 and COLOR_PAIRS-1. The - values that are stored at the addresses pointed to by the - second and third arguments are between 0 and COLORS. - - Colors + ters are displayed). A programmer initializes a color- + pair with the routine init_pair. After it has been ini- + 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- + nition of a color. The routines has_colors and + can_change_color return TRUE or FALSE, depending on + whether the terminal has color capabilities and whether + the programmer can change the colors. The routine col- + or_content allows a programmer to extract the amounts of + red, green, and blue components in an initialized color. + The routine pair_content allows a programmer to find out + 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. + + +
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 COLOR_GREEN @@ -170,96 +163,322 @@ COLOR_CYAN COLOR_WHITE + Some terminals support more than the eight (8) "ANSI" col- + ors. There are no standard names for those additional + colors. --
- 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 ERR") upon successful completion. - - 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_PAIR-1. Color values used in init_color must be in the - range 0 to 1000. An error is returned from all functions - if the terminal has not been initialized. An error is re- - turned from secondary functions such as init_pair if + +
+ +
+ is initialized by start_color to the maximum number of + colors the terminal can support. + + +
+ is initialized by start_color to the maximum number of + color pairs the terminal can support. + + +
+ +
+ 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. + start_color does this: + + 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 + pairs are initialized. + + 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) + capability, start_color initializes its internal table + representing the red, green and blue components of the + color palette. + + 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 + 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 + 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 + a runtime error: + + o COLORS corresponds to the terminal database's max_col- + ors capability, (see terminfo(5)). + + 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- + fault_colors). + + o COLOR_PAIRS corresponds to the terminal database's + max_pairs capability, (see terminfo(5)). + + 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 + actually whatever the terminal implements before color + is initialized. It cannot be modified by the applica- + tion. + + +
+ 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- + 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 + routine facilitates writing terminal-independent programs. + + +
+ 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- + ground. + + 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 + changed to the new definition. + + As an extension, ncurses allows you to set color pair 0 + via the assume_default_colors(3x) routine, or to specify + the use of default colors (color number -1) if you first + invoke the use_default_colors(3x) 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 + red, green, and blue components). + + o The first argument must be a legal color value; de- + fault colors are not allowed here. (See the section + Colors for the default color index.) + + o Each of the last three arguments must be a value in + 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 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 + the given color. + + o The first argument must be a legal color value, i.e., + 0 through COLORS-1, inclusive. + + o 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. + + o The first argument must be a legal color value, i.e., + in the range 1 through COLOR_PAIRS-1, inclusive. + + o The values that are stored at the addresses pointed 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 inverse COLOR_PAIR(n) 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 attr_set (which pass + the color pair as a separate parameter) rather than the + legacy functions such as attrset. + + +
+ 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 + ERR") upon successful completion. + + 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 start_color was not called. - init_color - returns an error if the terminal does not sup- - port this feature, e.g., if the initial- - ize_color capability is absent from the termi- - nal description. + init_color + 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 - allocated. + start_color + 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; + 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 - 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 - curs_bkgd(3x). Several caveats apply on 386 and 486 ma- - chines with VGA-compatible graphics: + shared color palette. - - COLOR_YELLOW is actually brown. To get yellow, use - COLOR_YELLOW combined with the A_BOLD attribute. + Setting an implicit background color via a color pair af- + fects only character cells that a character write opera- + tion explicitly touches. To change the background color + used when parts of a window are blanked by erasing or + scrolling operations, see curs_bkgd(3x). - - 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). + Several caveats apply on older x86 machines (e.g., i386, + i486) with VGA-compatible graphics: - - Color RGB values are not settable. + 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 + 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). --
- This implementation satisfies XSI Curses's minimum maxi- + o Color RGB values are not settable. + + +
+ 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 - first invoked. + The init_pair routine accepts negative values of fore- + ground and background color to support the use_de- + fault_colors(3x) 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- - sume_default_colors extension. + The assumption that COLOR_BLACK is the default background + color for all terminals can be modified using the as- + sume_default_colors(3x) 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. + X/Open Curses does not specify a limit for the number of + colors and color pairs which a terminal can support. How- + ever, in its use of short for the parameters, it carries + over SVr4's implementation detail for the compiled termin- + fo database, which uses signed 16-bit numbers. This im- + plementation provides extended versions of those functions + which use short parameters, allowing applications to use + larger color- and pair-numbers. --
- curses(3x), curs_initscr(3x), curs_attr(3x), default_col- - ors(3x) + +
+ curses(3x), curs_initscr(3x), curs_attr(3x), curs_vari- + ables(3x), default_colors(3x) curs_color(3x)-