[GRASS5] gis.m limitation

[Cedric Shock]

Trevor,

> On of the short comings with gis.m that I now find is that it is
> impossible to zoom to a file with the new interface since shell
> commands no longer affect the current window.

Shell commands do affect the region, which affects the window if it is 
redrawn. Currently there are two redraw buttons. The one on the left draws 
changes in layers. The one on the redraws everything and will draw correctly 
if the region has been changed.

I imagine that if I change the region and change a layer and use the left 
redraw button I'll get two layers rendered at different regions which is a 
bug. I just tried this and indeed it is so.

The correct thing for us to do is have one redraw button and a belief state 
about the region. If the region is not in our belief state we should assert 
that the layers are dirty and must be redrawn.

--Cedric