From 05f1f41c9b02b916a5f03c5658bec3270ac3684d Mon Sep 17 00:00:00 2001 From: Robert Estelle Date: Mon, 25 Oct 2021 22:32:36 +0000 Subject: [PATCH] color: support "default" to restore fg/bg color The name "default" can now be used in foreground or background colors, and means to use the terminal's default color, discarding any explicitly-set color without affecting the other attributes. On many modern terminals, this is *not* the same as specifying "white" or "black". Although attributes could previously be cleared like "no-bold", there had not been a similar mechanism available for colors, other than a full "reset", which cannot currently be combined with other settings. Note that this is *not* the same as the existing name "normal", which is a no-op placeholder to permit setting the background without changing the foreground. (i.e. what is currently called "normal" might have been more descriptively named "inherit", "none", "pass" or similar). Signed-off-by: Robert Estelle Signed-off-by: Junio C Hamano --- Documentation/config.txt | 18 +++++++++++++----- color.c | 23 ++++++++++++++++++++++- color.h | 4 ++++ t/t4026-color.sh | 12 ++++++++++++ 4 files changed, 51 insertions(+), 6 deletions(-) diff --git a/Documentation/config.txt b/Documentation/config.txt index 0c0e6b859f..636e722f30 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -262,11 +262,19 @@ color:: colors (at most two, one for foreground and one for background) and attributes (as many as you want), separated by spaces. + -The basic colors accepted are `normal`, `black`, `red`, `green`, `yellow`, -`blue`, `magenta`, `cyan` and `white`. The first color given is the -foreground; the second is the background. All the basic colors except -`normal` have a bright variant that can be specified by prefixing the -color with `bright`, like `brightred`. +The basic colors accepted are `normal`, `black`, `red`, `green`, +`yellow`, `blue`, `magenta`, `cyan`, `white` and `default`. The first +color given is the foreground; the second is the background. All the +basic colors except `normal` and `default` have a bright variant that can +be specified by prefixing the color with `bright`, like `brightred`. ++ +The color `normal` makes no change to the color. It is the same as an +empty string, but can be used as the foreground color when specifying a +background color alone (for example, "normal red"). ++ +The color `default` explicitly resets the color to the terminal default, +for example to specify a cleared background. Although it varies between +terminals, this is usually not the same as setting to "white black". + Colors may also be given as numbers between 0 and 255; these use ANSI 256-color mode (but note that not all terminals may support this). If diff --git a/color.c b/color.c index 64f52a4f93..a5fa9b79a7 100644 --- a/color.c +++ b/color.c @@ -40,7 +40,7 @@ struct color { enum { COLOR_UNSPECIFIED = 0, COLOR_NORMAL, - COLOR_ANSI, /* basic 0-7 ANSI colors */ + COLOR_ANSI, /* basic 0-7 ANSI colors + "default" (value = 9) */ COLOR_256, COLOR_RGB } type; @@ -83,6 +83,27 @@ static int parse_ansi_color(struct color *out, const char *name, int len) int i; int color_offset = COLOR_FOREGROUND_ANSI; + if (match_word(name, len, "default")) { + /* + * Restores to the terminal's default color, which may not be + * the same as explicitly setting "white" or "black". + * + * ECMA-48 - Control Functions \ + * for Coded Character Sets, 5th edition (June 1991): + * > 39 default display colour (implementation-defined) + * > 49 default background colour (implementation-defined) + * + * Although not supported /everywhere/--according to terminfo, + * some terminals define "op" (original pair) as a blunt + * "set to white on black", or even "send full SGR reset"-- + * it's standard and well-supported enough that if a user + * asks for it in their config this will do the right thing. + */ + out->type = COLOR_ANSI; + out->value = 9 + color_offset; + return 0; + } + if (strncasecmp(name, "bright", 6) == 0) { color_offset = COLOR_FOREGROUND_BRIGHT_ANSI; name += 6; diff --git a/color.h b/color.h index c20d324e7c..27e817016b 100644 --- a/color.h +++ b/color.h @@ -32,6 +32,7 @@ struct strbuf; #define GIT_COLOR_MAGENTA "\033[35m" #define GIT_COLOR_CYAN "\033[36m" #define GIT_COLOR_WHITE "\033[37m" +#define GIT_COLOR_DEFAULT "\033[39m" #define GIT_COLOR_BOLD_BLACK "\033[1;30m" #define GIT_COLOR_BOLD_RED "\033[1;31m" #define GIT_COLOR_BOLD_GREEN "\033[1;32m" @@ -40,6 +41,7 @@ struct strbuf; #define GIT_COLOR_BOLD_MAGENTA "\033[1;35m" #define GIT_COLOR_BOLD_CYAN "\033[1;36m" #define GIT_COLOR_BOLD_WHITE "\033[1;37m" +#define GIT_COLOR_BOLD_DEFAULT "\033[1;39m" #define GIT_COLOR_FAINT_BLACK "\033[2;30m" #define GIT_COLOR_FAINT_RED "\033[2;31m" #define GIT_COLOR_FAINT_GREEN "\033[2;32m" @@ -48,6 +50,7 @@ struct strbuf; #define GIT_COLOR_FAINT_MAGENTA "\033[2;35m" #define GIT_COLOR_FAINT_CYAN "\033[2;36m" #define GIT_COLOR_FAINT_WHITE "\033[2;37m" +#define GIT_COLOR_FAINT_DEFAULT "\033[2;39m" #define GIT_COLOR_BG_BLACK "\033[40m" #define GIT_COLOR_BG_RED "\033[41m" #define GIT_COLOR_BG_GREEN "\033[42m" @@ -56,6 +59,7 @@ struct strbuf; #define GIT_COLOR_BG_MAGENTA "\033[45m" #define GIT_COLOR_BG_CYAN "\033[46m" #define GIT_COLOR_BG_WHITE "\033[47m" +#define GIT_COLOR_BG_DEFAULT "\033[49m" #define GIT_COLOR_FAINT "\033[2m" #define GIT_COLOR_FAINT_ITALIC "\033[2;3m" #define GIT_COLOR_REVERSE "\033[7m" diff --git a/t/t4026-color.sh b/t/t4026-color.sh index cc73161b46..d6907a66c3 100755 --- a/t/t4026-color.sh +++ b/t/t4026-color.sh @@ -96,6 +96,18 @@ test_expect_success '24-bit colors' ' color "#ff00ff black" "[38;2;255;0;255;40m" ' +test_expect_success '"default" foreground' ' + color "default" "[39m" +' + +test_expect_success '"normal default" to clear background' ' + color "normal default" "[49m" +' + +test_expect_success '"default" can be combined with attributes' ' + color "default default no-reverse bold" "[1;27;39;49m" +' + test_expect_success '"normal" yields no color at all"' ' color "normal black" "[40m" '