Re: [Qemu-devel] [F.A.Q.] the advantages of a shared tool/kernel Git repository, tools/perf/ and tools/kvm/

[Ingo Molnar <mingo@elte.hu>]

* Gerd Hoffmann <kraxel@redhat.com> wrote:

> > For reference, the default set of colors now is (from
> > tools/perf/util/ui/browser.c):
> > 
> > static struct ui_browser__colorset {
> >         const char *name, *fg, *bg;
> >         int colorset;
> > } ui_browser__colorsets[] = {
> >         {
> >                 .colorset = HE_COLORSET_TOP,
> >                 .name     = "top",
> >                 .fg       = "red",
> >                 .bg       = "default",
> 
> Bad idea IMO.  Setting only one of foreground+background gives 
> pretty much unpredictable results.  My xterms have different 
> background colors, the ones with a root shell happen to have a 
> (dark) red background. Which results in red-on-dark-red text.  Not 
> good.
> 
> I'd strongly suggest to either set both background and foreground 
> to default or to set both to a specific color.  When doing the 
> latter make sure the colors have enougth contrast so they are 
> readable.

Indeed.

What we want to have is to have a set of distinctive colors - just 
two (background, foreground) colors are not enough - we also need 
colors to highlight certain information - we need 5-6 colors for the 
output to be maximally expressive. Is there a canonical way to handle 
that while still adapting to user preferences automatically by taking 
background/foreground color scheme of the xterm into account?

I suspect to fix the worst of the fallout we could add some logic to 
detect low contrast combinations (too low color distance) and fall 
back to the foreground/background colors in that case.

Plus allowing full .perfconfig configurability of all the relevant 
colors, for those with special taste.

Thanks,

	Ingo