[GRASS5] d.rast, d.what.rast multiple query

[Glynn Clements]

Jaro Hofierka wrote:

> Well, I think a default behavior of displaying raster maps in monitor 
> window should be the monitor "remembers" just current map. So when I use 
> d.what.rast, or resize the monitor window I get just the last map, not 
> last 10-15 maps. Usually then I have to use d.erase and repeat it again.
> But I have to say that it is not wrong to have such behavior of d.rast 
> or d.what.rast. But I would add such a option (querying multiple 
> recently displayed maps) as the option explicitly requested by a user 
> (e.g. using -m option in d.what.rast).

The problem is that the monitor doesn't really know what a "map" is. 
The monitor maintains a set of "pads", which are basically just lists
of strings. The redraw code just traverses specific pads (which are
known to contain display commands), and executes those commands. It
doesn't know that certain commands will obscure the output from other
commands.

Most of the display management is a hack, and is bound to have rough
edges. The only solution is to actually design the interface
architecture, rather than just tacking on features on an ad-hoc basis.

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