[GRASS5] d.leg.thin fixes

[Glynn Clements]

Helena wrote:

> > I have added a -v and -c flag for d.legend compliance, and fixed a
> > bug when using the mouse for CELL type.
> >
> > Except that NULL is not shown (do we want this?) the functionality
> > of d.leg.thin shall cover now that of d.legend (and provide more).
> 
> is it possible to define a color for NULL? I believe that it is always
> white.
> If that is true you probably don't need to have it in legend.

Well, colour tables don't have an entry for NULL, but d.rast allows it
to be set with the "bg=" option; also, NULL can be transparent (e.g. 
"d.rast -o ...", in which case the colour will be that used for the
last call to d.erase. And even if it was always white, this might not
be obvious to the user, so it may be worthwhile including it in the
legend.

I think that d.legend/d.leg.thin should have an option to set the NULL
colour, and a flag to select whether to display an entry for it (then
the only issue is whether it is on or off by default).

-- 
Glynn Clements <glynn.clements at virgin.net>