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=b385da464dfbbfaed7cffff9d88ee774d924fc27;hb=f344f8539c1543f8cd65a5bb142dbaf23b9421d2;hpb=b0b1980be11bba618d84beb8b30ac94e2c820602;ds=sidebyside diff --git a/doc/html/man/curs_color.3x.html b/doc/html/man/curs_color.3x.html index b385da46..cf446d17 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 + 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); --
- Overview - 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- @@ -91,18 +97,87 @@ The routine pair_content allows a programmer to find out how a given color-pair is currently defined. - Routine Descriptions + +
+ 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. - 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. + 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 @@ -200,10 +275,21 @@ to by the second and third arguments are in the range 0 through COLORS, inclusive. - Colors + 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 @@ -215,10 +301,9 @@ 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 @@ -236,7 +321,7 @@ init_color returns an error if the terminal does not support - this feature, e.g., if the initialize_color capa- + this feature, e.g., if the initialize_color capa- bility is absent from the terminal description. start_color @@ -244,9 +329,8 @@ 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. @@ -276,8 +360,7 @@ o Color RGB values are not settable. --
+
This implementation satisfies XSI Curses's minimum maxi- mums for COLORS and COLOR_PAIRS. @@ -295,8 +378,7 @@ will treat those as optional parameters when null. --
+
curses(3x), curs_initscr(3x), curs_attr(3x), curs_vari- ables(3x), default_colors(3x) @@ -304,7 +386,23 @@ curs_color(3x)-