Re: col_inverse_bg=0 && col_inverse_fg=7

On Sat, 13 Nov 2010, Dennis Preiser wrote:

> While playing with colors I found the following issue which happens in
> the USE_CURSES && HAVE_USE_DEFAULT_COLORS case:
>
> It's not possible to set col_inverse_bg=0 (black) and col_inverse_fg=7
> (white). tin uses the (terminal) default fg an bg colors instead and
> thus the inverse bar gets 'invisible'. Steps to reproduce:
>
> open 'xterm -fg yellow -bg blue', start tin
>    'M'enu
> 	Draw -> instead of highlighted bar  : OFF
> 	Use inverse video for page headers  : ON
>    Standard foreground color           : Default
>    Standard background color           : Default
>    Color for inverse text (foreground) : White
>    Color for inverse text (background) : Black
>
> -> the inverse bar is 'invisible'.
>
> What happens: During startup use_default_colors() (in
> tcurses.c:InitScreen()) assign terminals fg and bg to color pair 0.
> Later on, color.c:set_colors() checks if the given fcolor and bcolor
> matches COLOR_WHITE and COLOR_BLACK. If so, color pair 0 is used.
> Unfortunately, for HAVE_USE_DEFAULT_COLORS, color pair 0 may hold other
> color informations. For col_inverse_bg=0 && col_inverse_fg=7 this
> results in an inverse bar with standard fg/bg -> the bar is 'invisible'.
>
> The following fixes this for me, alas I'm not an curses expert so I
> might be wrong:
>
> diff -urp tin-1.9.6/src/color.c tin-1.9.6_r2/src/color.c
> --- tin-1.9.6/src/color.c	2010-05-07 16:00:53.000000000 +0200
> +++ tin-1.9.6_r2/src/color.c	2010-11-12 18:01:32.000000000 +0100
> @@ -110,8 +110,12 @@ set_colors(
> 		if (bcolor > 0)
> 			bcolor %= COLORS;
>
> +#		ifdef HAVE_USE_DEFAULT_COLORS
> +		if (fcolor != default_fcol || bcolor != default_bcol) {
> +#		else
> 		/* curses assumes white/black */
> 		if (fcolor != COLOR_WHITE || bcolor != COLOR_BLACK) {
> +#		endif /* HAVE_USE_DEFAULT_COLORS */
> 			struct LIST *p;
> 			t_bool found = FALSE;
>
> default_fcol and default_bcol are either white/black or, if
> use_default_colors() succeeds, -1/-1 (default colors from terminal).

something like that (I'd be inclined to fold the two if-lines together
by defining DEFAULT_FCOL and DEFAULT_BCOL somewhere, and using those
for cases like this).

-- 
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net